DIP Episode 334 - USMLE Step 2CK Rapid Review Series 62
Topic
Genetic storage disorders; Peroxisomal metabolism; Zoonotic infections (Brucellosis, Leptospirosis); Spirochetal diseases (Lyme, Anaplasmosis, Babesiosis).
Key Takeaway
Mastering the differential diagnosis of infectious and metabolic syndromes—especially distinguishing between genetic lipid storage disorders (Tay-Sachs vs. Niemann-Pick) and differentiating co-infections in spirochetes (Anaplasmosis vs. Babesiosis)—is crucial for high-yield board performance.
Episode Notes
Source / episode info
- Episode: 334
- Title: Divine Intervention Episode 334 – USMLE Step 2 CK Rapid Review Series 62
- Published: 2021-08-17
- Source: Episode page
One-liner
This episode provides a rapid review of critical topics including genetic lipid storage disorders (Tay-Sachs and Niemann-Pick), peroxisomal metabolism defects (Zellweger syndrome), and key zoonotic/spirochetal infections like Leptospirosis, Brucellosis, and Lyme disease complex.
High-yield summary
- Tandem Diagnosis: Distinguish Tay-Sachs (GM2 ganglioside buildup, neuronal focus) from Niemann-Pick (Sphingomyelinase deficiency, hepatosplenomegaly, lipid-laden macrophages).
- Peroxisomal Failure: Zellweger syndrome results from PEX gene mutations, impairing the breakdown of very long-chain fatty acids (VLCF As), leading to multisystem failure.
- Leptospirosis Exposure: Think "dirty water" or "plumber." Diagnosis involves ELISA for IgM antibodies; confirmatory testing includes microscopic agglutination test/darkfield microscopy.
- Lyme Disease Complex: Borrelia burgdorferi is transmitted by X-A-D's ticks and can cause erythema migrans (EM) rash, CN VII palsy, and cardiac involvement (AV block).
- Infectious Anemia Differentiation: Remember the specific hematological pattern: Anaplasmosis = Pancytopenia; Babesiosis = Hemolytic anemia (Hgb low); Ehrlichiosis/Anaplasma = Thrombocytopenia.
- Antibiotic Safety: Doxycycline is a cornerstone for many zoonotic infections, but caution is required due to photosensitivity (Sulfonamides, Aminoglycosides, Tetracyclines).
Learning objectives
- Differentiate between the biochemical defects and clinical presentations of GM2 ganglioside storage disorders (Tay-Sachs vs. Niemann-Pick).
- Recognize the signs, symptoms, and diagnostic workup for peroxisomal disorders like Zellweger syndrome.
- Identify high-risk exposures and key laboratory findings associated with leptospirosis and brucellosis.
- Master the differential diagnosis of spirochetal infections (Anaplasmosis, Babesiosis, Lyme) based on clinical presentation, exposure, and specific hematological patterns.
- Understand the principles of antibiotic stewardship for zoonotic diseases, including recognizing photosensitivity risks.
Board exam buzzwords
| Condition | Key Finding | Association | Board Exam Tip |
| Tay-Sachs Disease | Cherry spot macula; Neurodegeneration | Hexosaminidase A deficiency; GM2 ganglioside buildup | Remember the specific populations (Ashkenazi Jewish, French Canadian). |
| Niemann-Pick Disease | Hepatosplenomegaly; Lipid-laden macrophages | Sphingomyelinase deficiency; Reticuloendothelial system storage | If H/S is present with lipid histopathology, think Niemann-Pick. |
| Zellweger Syndrome | Elevated VLCF As (Plasma); Hypotonia | Peroxisomal disorder (PEX gene mutation) | Failure of peroxisomes impairs the breakdown of very long chains. |
| Leptospirosis | Conjunctival injection; Fever/Myalgias | Exposure to animal urine or contaminated water | Diagnosis requires ELISA for IgM, confirmed by microagglutination test. |
Rapid review table
| Topic | Key Point | Context | Exam Relevance |
| Tay-Sachs vs Niemann-Pick | H/S + Lipid Macrophages = Niemann-Pick | Both are lysosomal storage disorders; the organ involvement is key. | Distinguishing these two requires knowing which enzyme deficiency causes which specific accumulation pattern. |
| Zellweger Syndrome | VLCFA buildup due to peroxisomal failure | Autosomal recessive, multisystemic disorder affecting lipid metabolism. | High-yield metabolic question testing knowledge of organelles and fatty acid breakdown pathways. |
| Leptospirosis | Exposure: Dirty water/animal urine; Symptoms: Conjunctivitis, fever | Diagnosis is often challenging due to non-specific symptoms. | Always consider the source (dirty water) when seeing this constellation of signs. |
| Lyme Disease Coinfections | Anaplasmosis = Pancytopenia; Babesiosis = Hemolytic anemia | Both are tick-borne and require Doxycycline, but their hematological signatures differ. | Use the specific blood count pattern to differentiate these infections on board exams. |
Board-speak -> diagnosis
| Board-speak / Vignette phrase | Diagnosis / Concept | Why it fits |
| A 6-month-old child from a French Canadian community presents with progressive neurodegeneration and cherry-red spot on the macula. | Tay-Sachs Disease (Hexosaminidase A deficiency) | Classic triad: Neurodegeneration, specific population risk, GM2 ganglioside buildup leading to retinal accumulation. |
| A young child presents with hepatosplenomegaly, thrombocytopenia, and lipid-laden macrophages found in the reticuloendothelial system. | Niemann-Pick Disease (Sphingomyelinase deficiency) | The presence of massive organ involvement (H/S) and specific macrophage histology points away from Tay-Sachs. |
| A child presents with progressive vision loss, hypotonia, and elevated very long-chain fatty acids (VLCF As). | Zellweger Syndrome | Indicates a peroxisomal disorder failure; VLCFA breakdown is impaired in the absence of functional peroxisomes (PEX gene mutation). |
| A plumber working after exposure to dirty water develops fever, myalgias, conjunctival injection, and signs of organ failure. | Leptospirosis (Leptospira interrogans) | Classic occupational/environmental exposure; severe systemic illness with renal/hepatic involvement. |
| A patient presents with a rash in the pattern of an expanding bullseye on the extremities after hiking in New England. | Lyme Disease (Borrelia burgdorferi) | The classic EM rash is highly suggestive, and the geographic location (New England) supports this diagnosis. |
| A child from a rural area consuming unpasteurized milk develops fever, myalgias, and signs of systemic infection. | Brucellosis (Brucella spp.) | Associated with livestock exposure and consumption of raw dairy products; requires specific antibiotic treatment. |
Differential diagnosis / distinguishing features
Spirochetal Infections (Anaplasmosis vs Babesiosis)
| Key Features | Distinguishing Findings | Next Step |
| Anaplasmosis | Pancytopenia (low WBC, RBC, PLT); Flu-like illness | Diagnosis often requires PCR or serology; treat empirically with Doxycycline. |
| Babesiosis | Hemolytic anemia (Hgb low only); Multi-spore pattern on blood smear | Blood smear review is critical for identifying the organism's morphology. Treat with Atovaquone + Nitazoxanide. |
Leptospirosis vs Lyme Disease
| Key Features | Distinguishing Findings | Next Step |
| Leptospirosis | Exposure: Dirty water, animal urine; Conjunctival injection | Diagnosis requires ELISA for IgM antibodies against Leptospira. |
| Lyme Disease | Exposure: New England/hiking; Rash: Erythema migrans (EM) | Diagnosis is clinical and geographic; treat with Doxycycline. |
Management pearls
- Zoonotic Infections: For most suspected zoonoses (e.g., Brucellosis, Anaplasmosis), Doxycycline is the drug of choice due to its broad spectrum.
- Lyme CNS Involvement: If Lyme disease involves the central nervous system (meningitis) or heart (AV block/3rd degree block), IV antibiotics like IV Ceftriaxone or IV Cephroxin are required.
- Leptospirosis Diagnosis: Initial screening is an ELISA for IgM antibodies; confirmation requires a microscopic agglutination test.
- Antibiotic Safety: When administering Doxycycline, the patient must be warned about photosensitivity (avoid sun exposure).
Don't miss
Integration & clinical reasoning
- Metabolic Integration: The failure of peroxisomal function (Zellweger) and lysosomal storage defects (Tay-Sachs, Niemann-Pick) both illustrate the critical role of cellular organelles in maintaining metabolic homeostasis.
- Infectious Disease Integration: Many zoonotic infections (Leptospirosis, Brucellosis, Lyme) share common treatment principles (Doxycycline use), but their specific exposures and diagnostic tests are unique.
- Antibiotic Principles: The concept of drug resistance and the need for combination therapy is highlighted by treating Babesiosis with Atovaquone + Nitazoxanide.
OMM / COMLEX integration
- Acute/Unstable Management: In cases of suspected severe sepsis or acute organ failure secondary to zoonotic infections (e.g., leptospirosis), standard emergency management (IV fluids, vasopressors, broad-spectrum antibiotics) takes absolute priority over OMT.
- Infectious Etiology: Understanding the source and transmission route (zoonosis) is critical for both clinical diagnosis and public health measures (e.g., milk pasteurization).
Concept connections / cross-references
- For a deeper dive into general infectious disease principles, review [ Episode 123 ] (if available).
- For detailed coverage of genetic metabolic disorders, see [ Episode 456 ].
- For comprehensive reviews on microbiology and zoonoses, refer to [Episode 789].
High-yield association table
| Condition | Association | Mechanism | Clinical Significance |
| Tay-Sachs Disease | Hexosaminidase A deficiency | Buildup of GM2 ganglioside in lysosomes. | Leads to progressive neurodegeneration and cherry-red spot macula. |
| Niemann-Pick Disease | Sphingomyelinase deficiency | Buildup of sphingomyelin in the reticuloendothelial system (spleen/liver). | Causes hepatosplenomegaly, thrombocytopenia, and lipid accumulation in macrophages. |
| Zellweger Syndrome | PEX gene mutation | Failure of peroxisomal beta-oxidation of VLCF As. | Leads to severe multisystem failure affecting the nervous system and liver. |
| Leptospirosis | Dirty water/Animal urine exposure | Infection by Leptospira interrogans. | High risk for renal and hepatic failure; diagnosis requires specific serology (ELISA). |
Key terms glossary
| Term | Definition | Context | Example |
| GM2 Ganglioside | A type of ganglioside lipid that accumulates in lysosomes. | Lysosomal storage disorders, specifically Tay-Sachs disease. | Buildup leads to neuronal death and the characteristic cherry-red spot. |
| Peroxisome | Organelle responsible for breaking down very long-chain fatty acids (VLCF As). | Metabolic disorders like Zellweger syndrome. | Mutation in PEX genes impairs VLCFA breakdown, leading to systemic toxicity. |
| Erythema Migrans (EM) | A classic expanding rash with a bullseye pattern. | Lyme disease (Borrelia burgdorferi). | Highly suggestive of early localized infection and requires prompt antibiotic treatment. |
| Pancytopenia | Reduction in all three blood cell lines (RBC, WBC, Platelets). | Seen in Anaplasmosis or other systemic infections; indicates bone marrow suppression/consumption. | Differentiating pancytopenia from isolated thrombocytopenia is key for diagnosis. |
Study optimization
| Topic | Study Approach | Priority | Resources |
| Genetic Storage Disorders | Create a comparison table (Enzyme deficiency, Accumulating substrate, Key organ involvement). | High | Review board-specific mnemonics and classic populations (e.g., Ashkenazi Jewish for Tay-Sachs). |
| Zoonotic Infections | Focus on the triad: Exposure source -> Clinical signs -> Specific treatment/diagnostic test. | Medium-High | Use flowcharts to map exposure (e.g., dirty water -> Leptospirosis). |
| Differential Diagnosis of Anemia | Memorize the specific hematological pattern for each infection type. | High | Practice questions comparing pancytopenia vs. hemolytic anemia vs. isolated thrombocytopenia. |
Question pattern recognition
- Genetic/Metabolic Pattern: If a question involves progressive neurodegeneration in infancy, consider lysosomal storage disorders (Tay-Sachs) or peroxisomal defects (Zellweger). The specific organ failure and enzyme deficiency will guide the diagnosis.
- Infectious Exposure Pattern: Always link the clinical presentation to the source of infection (e.g., dirty water -> Leptospirosis; farm/raw milk -> Brucellosis).
- Spirochete Differentiation Pattern: When presented with a tick-borne illness, immediately assess the patient's blood counts and rash pattern to differentiate Anaplasmosis (pancytopenia), Babesiosis (hemolytic anemia), or Lyme disease (EM rash/CN palsy).
Test yourself
Common mistakes to avoid
Common traps
Original transcript with highlights
Original transcript with highlights
Okay, welcome. My name is Devine. This is episode 334 of the Devine Intervention podcast. And then this podcast will be continued in our rapid review series for the USM and the list of 2 CK exam. This will be series 62. As I do, I know many people are going to be taking a step to CK very soon over the next couple of weeks here because as I know, there's a quite a number of people that want to get their scores before the era's deadline of September 29th. So if you're taking your exams soon, I'll encourage you to sign up for the course I have coming up next week. Again, many people have attended these courses and they've done really well with the exams. So next week Wednesday the 25th of August, we have the MBME Testicking Strategies class. Again, you'll basically learn how to take MBME tests, not for loopholes. Basically, if you're a bad test-taker, take the course and become a much better test-taker. I mean, I get very positive feedback all the time from people that, oh, Devine, I took your course like a few days. You know, I took a practice exam, a few days prior. And then I took the test-ticking Strategies course. And now my scores have just gone through the roof. My scores have shut up. And then I have the comprehensive review course first step to CK and also for step three. It's going to be the increase from Thursday to Saturday next week.
We're going to be covering internal medicine, Peds, general surgery, psych, OB-GYN, Neural, Ethics, Bio STA Ts, professionalism, communications, healthcare systems, multi-system processes, and disorders. So we'll pretty much have a very good, and it's not going to be like lecture-based because again, I don't believe in given stock lectures. So we're going to use entirely scenarios for about like 99% of what we deal with. So we're going to be using scenarios. We end up going to about 2000 concepts roughly for the USM Ls, the CKSTAT 3 exams. So if you're interested, the course is going to be held over Zoom, take it from the comfort of your home. Just should be an email through the website and I'll give you some more details on cost. Once you've paid the invoice, I send to you then your spot will be reserved in the course. Okay, so let's just get ready into it. So what if they give you a question about a six month old child? And tell you that this child is losing Muromile stones, right? And they tell you that, you know, this child for the last three months, the child has been not able to sit. This child is not able to turn over. This child is not able to crawl. The tell you of all the seizures that this child has had. And they tell you that when his mom calls him, he doesn't respond, right? And they tell you that all this child lives in a small like French Canadian community or a small, Amish community in Pennsylvania. If you see this, what are you thinking about?
I really hope you're saying, oh, divine. It sounds like this person has T-Sax disease, right? So again, for those of you taking step to CKSTAT 3, I was just really hope you remember that. They do test these genetic diseases time and time again. There's no something you can just ignore, you know? So this is T-Sax disease. Remember, T-Sax disease was the pathophage. Remember, the horizon is from a hexosamene disease, A, deficiency, right? So when you have the deficiency of hexosamene disease, A, the thing that's going to happen is you're going to have a buildup of GM2 gangliocyte, right? GM2 gangliocyte, I mean, look at the name gangliocyte, right? So gangliot, right? So it's only related to neurons. So the thing is, it's a single lipid that will build up and then you'll pretty much descend and destroy your neurons, right? And they're certain key populations that the MBM is love to put these things in, right? So do you know there's the Ashkenazi Jewish population that pretty much everyone has committed to memory, right? But beyond that, remember, you can also find these on MBM exams in French Canadians. You can find this in the Amish of the Amish of population of a Pennsylvania, right? And you can also find these in the Cajuns of Southern Louisiana, right? And classically on MBM exams, these kids will have a charred spot on the macula, right? These kids will have a charred spot on the macula and you may wonder, oh, why do they have this charred spot on the macula?
Well, it's not that complicated. Basically, the macula is going to stand out compared to all the other right now gangliot cells that have been distended with this as finger lipid, right? So you also want to an MBM exams be able to compare and contrast T-Sax disease with Mimand Pick disease. Mimand Pick disease is like the plus cousin of T-Sax disease. Now the thing is in Mimand Pick disease, you have a deficiency of an enzyme called Mimand Pick disease, right? S-P-H-I-N-G-O-M-Y-E-L-I-N-A-S-E. It's finger Mimand Pick disease, right? So you have a deficiency of finger Mimand Pick disease, so finger Mimand Pick disease is going to be old up. The thing is finger Mimand Pick disease is an enzyme that found a lot in macrophages, right? And we know that macrophages, they are big component of the reticulary endothelial system. Basically, the reticulary endothelial system is your lever just to simplify things for purposes of the exam, is your lever in your spleen, right? So the thing is, and you know, it's also an enzyme we find in, finding neurons, right? So the thing is these kids, because of the sphingo-miling that's building up in these macrophages of their reticulary endothelial system, they're going to have a hepatosplenomegaly, right? You know, remember, whenever you have spleenomegaly, when your spleen gets bigger, it's going to sequester some pleaklets, right? So these kids also tend to have a thrombocytopenia, right?
But again, because this thing, because this sphingo-miling is also finding neurons, right? They will also have this chairretz put on the macula, right? But again, very important, they'll have the chairretz put on the macula, but they will also have a hepatosplenomegaly. Hepatosplenomegaly, on nimbim exams, is not a finding in T-Sax disease. It is a finding in nim and pick disease, right? And it's very high you to know that in nim and pick disease, they will tell you that these macrophages that you see on histology, they are lipid leading, right? So if you see this cluster of symptoms and then they tell you that, oh, on histology, you see lipid leading macrophages. They're pretty much guiding you towards nim and pick disease. Again, that lipid in the macrophages are those sphingo-miling that are building up because you have this sphingo-miling is deficiency. Again, I will encourage you when you're studying for exams, try to understand as much as you can. That's why you cannot leave your studying for the last minute. When I hear people saying they are cramming for an exam, it's always kind of sad, because you're pretty much going to, in most cases, be performing a lot less than what your potential can be. Your potential can be much better if you just spend time really getting material down. You see people they want to complete like an entire u-world cubank in two weeks. Again, is that something bad to do? No, it's not bad, it's better than nothing, right?
But you'll probably have been better if you kind of spread that over a longer period of time. So you can actually really get something from that past, right? That's why many times you don't see me recommending two passes of a human to people because if you make one good, slow, solid pass, you get a lot from it, right? It's always good to expose yourself to any questions. Okay, let me hear if my soapbox here, let's continue. So, what if they give you a question about a two-year-old female and detail that she has been having progressive vision loss, progressive hearing loss over the last few months, right? And then they tell you that at birth, she was extremely hypotonic. And then they tell you that on physical exam, you know, she has a phallus plenomegaly, right? And then they tell you that, oh, the do some testing on her plasma and the notice very elevated levels of very long-chain fatty acids, right? Elevated levels of very long-chain fatty acids. If you see stuff like this, what should you be thinking about? I'll really hope you're thinking about Zellweger syndrome, right? So Zellweger is spelled at Z-E-W-L-W-E-W-G-E-R Zellweger syndrome, right? So the thing is this is actually a peroxisomal disorder, right? So, remember, your mitochondria helps you bring down, break down, medium and long-chain fatty acids. But the breakdown, or we can see beta-oxidation, of very long-chain fatty acids, occurs in the peroxysome, right?
So the thing is, if you have a pex, P-E-X, a pex gene mutation, then you're going to have trouble breaking down very long-chain fatty acids, right? So, your very long-chain fatty acids, your branching fatty acids, those things are going to build up, and it's going to cause problems, right? So you're going to have, like, my initial problems and all those issues, right? So this person has a Zellweger syndrome, basically things that depend on lipid breakdown, right? You're going to have problems with that, right? So, that's Zellweger syndrome, remember, it's in Herifet, in an autosomal recessive fascia, right? So you can happen in shopping, both boys and girls on NBME exams. Okay, now what if they give you a question about a five-year female and they tell you that, you know, they bring her to the emergency room, that for the last, like, 10 days, she's been having, like, daily morning fevers, and they tell you that this girl lives on a farm, and she consumes a lot of good milk, you know? They live in a rural area, good milk, readily available, right? And then they tell you that her parents tell you that, you know, she, the notice that this child just seems to sweat a lot, just big-time sweating at night, and by morning, when they check this child's underwear, the underwear just smells really bad, has this very fast-melting order, right?
And then they tell you that this child is complaining of, like, left knee pain, right hip pain, and then they give you some laps, and you notice that this child has a locomotive, so the white count is like 1,000, and you notice that the hematocreat is like 28%. Right? So if you kind of put all these things together, you know, these kind of looks like a non-specific presentation, right? But again, you see, there's been going over 10 days, right? So you probably, I would hope, you're not thinking, like, some genetic disease, right? You're thinking more along the lines of an infectious disease, right? You see this person works our own form animals, having these fevers that seem to come and go far body-order, right? This is broselosis, right? So this person has broselosis. Remember, broselosis, another name the user name being is for this stuff. The user of the term, on-doland fevers, right? On-doland fevers is caused by brosela, right? And how do we treat this? So typically, on any name-in-exams, I'm going to treat this with a drug combination of, I think of this as the doctor-drug combination, right? What I'm doing in my doctor, my doctor, I mean, you give doxicin and rifamping, right? Another alternative is you can give doxicin and amino glycoside, right? So remember, sometimes, you know, they still do these, although it's usually pretty minimal, right? Sometimes they still do these identification questions. Remember, it's a gram-negative bulk, right?
It's a gram-negative, facultatively intracellular, coco-bacillus. But I think knowing that it's gram-negative and it's coco-bacillus is probably the most important thing for step two, see case step three, right? Now, it's kind of high yield to know that many of these kids, you know, they'll have like a lot of nausea and vomiting and they'll have a elevated liver function tests, right? And again, because we live in this preventive medicine age with a USML exams, they can ask, how could we have prevented this person from acquiring this infection in the first place? Well, the answer you want to pick is pasteurizing their milk, right? When you pasteurize milk, then you don't get into all these problems, right? So pasteurizing the milk would have prevent, you know, physically hitting the milk up to kill all the bugs in it or make them not get a brissela, right? And then just as a high yielded bit, this child that lives on a farm and consumes a good milk, is there a particular kind of anemia they could have? Well, I would hope you're really saying, oh, these kids could have, this child could have a megaloblastic anemia, right? From fully deficiency. Remember, good milk is very pointfully, right? So if you see a child lives on a farm, lives in a rural area, he's parents are like good farmers or whatever, and you see this child make a lumblastic anemia, think of fully deficiency as the cause, right?
Remember, obviously you're going to see high-pressigmented neutral fields on, on histology in those circumstances. Okay, now what if they give you a question about a plumber? They tell you that this person has a plumber and for the last three days he has been having like very severe abdominal pain, having a lot of myalgias, having chills, having high fevers, having like a frontal headache. And then they tell you that they perform physical exam and you notice that on phondoscopy, this person has like bilateral congenital injection, right? And you notice that this person's ASTLT is very, very high, right? And you notice that this person is creatinine, these two. So this person is not doing well, they're keeping his, they're going to shut down, the liver is going to shut down, right? And we see this person has a plumber, this person that's potentially exposed to like dirty water, if you see something like this, I really hope you're thinking about leptospheroces, right? Remember, leptospheroces is caused by leptospiring interrogants, right? So you know, they are many different ways to contest these, if you, if they give you a question and revolving around, why is probably going to be a leptospheroces question? Or if they give you a question revolving around, that's a person that is like a sewage worker, or a person that applies fertilizer, right?
Or a person that works with like just dirty water, like a plumber, or a person that works like, like does like a lot of like water work. In those circumstances, I really want you to think about leptospheroces. If you remember, leptospheroces is caused by leptospire interrogants, right? And the thing is sometimes, are friends that the MBMD get very coy, right? Instead of putting the term leptospheroces on an exam, they can put spiraledine infection as an answer, right? That's why you see people, they take the exam and when they are walking out, they feel like they've just had to guess off through a lot of it because you're already in the question, you're like, oh, I know what this is. But then you look at the answer choices and what you think it is, it's not one of the answer choices, right? The MBMD is these days, they do these things I call a derivative answers, right? They put an answer that relates to what is the right answer, but it's not exactly what the right is, not exactly the right answer you're looking for. So that's something you want to be careful about, right? So they can put the word spirochet on the test, right? So remember, they can put the word spirochet for leptospire, they can put the word spirochet for Lyme disease, they can put the word spirochet for syphilis, right? Those are the three high-end spirochids to know for your exams, right? So what is the mode of transmission of leptospheroces?
Well, remember, you get the stuff when you're exposed to animal urine, right? So how do we treat this? The theme is many of these weird infectious diseases, if you're kind of like, I don't know what to remember for an exam, just remember doxyscycline, doxyscycline is a very good drug for treating many of these weird zoonotic infections, right? So doxyscycline, you can also use a macrolyzo, is great for treating leptospheroces. So how do we diagnose leptospheroces on MBMD exams? Well, the first thing is you're going to do an eliza, right? You're going to do an eliza, you're basically looking for IGM antibodies against leptospire interrogants, right? And then what do you do as a, because remember, in medicine, after you do a screening test, you need to follow that up with some kind of confirmatory test, right? So what's the confirmatory test for that? Well, the confirmatory test is something I call the microscopic adglutination test, right? The microscopic adglutination test. Sometimes you can even pair that up with like darkfield microscopy. Remember darkfield microscopy is very good with directly for direct visualization of spirochids, right? So you can do darkfield microscopy, right? So the thing is what is, again, we live in this race factors, preventive medicine, prognostic factor world on MBM Ds, right? So what's the thing that usually predicts a person having really poor outcomes from leptosplerosis? Well, the thing I would say is think of long involvement.
If there are, if your lungs are involved, the mortality rate is at least to like 50 to 70 percent, right? So a person absolutely does not want to get pulmonary leptosplerosis, pulmonary leptosplerosis is very deadly, right? I mean, is there one more deadly than having ERDS, right? It's one more deadly than having ERDS. So again, it's just something kind of key and high you to keep in mind for, for example. Okay, now what if they give you a question about a, you know, 27-year-old male and they tell you that he has like a non-pinful, non-achie, you know, like stracholorations offer extremities, right? And it's been growing, growing, growing, growing, growing, growing in size over the last like three days, right? And then he tells you that, you know, he's had a mild headache, he's been having fever, he's been having chills, and he tells you that, you know, he actually went on a hike with a few friends to like some place in a New Hampshire, right? And then the tell you on physical exam, the tell you that this rush has like an area terminal center. If you see this, right, this is pretty easy. This person has Lyme disease, right? This person has Lyme disease, right? So remember Lyme disease was the bug that causes Lyme disease. Remember it's Borrelia book Dofery, right? Remember Borrelia book Dofery, as I said, it's a Spiroket. And this Spiroket is actually carried by the X-A-D's tech, it's carried by the X-A-D's tech, right?
So the thing is, it's actually kind of higher to know a lot more than is normal for most other subjects about Lyme disease. Lyme disease is just something you know, you're probably going to see tested on you exam, right? And again, do you know, always give you that new England association, do you mean, give you like an exotic area like Minnesota, stuff like that, right? So remember Lyme disease again, caused by Borrelia book Dofery is carried by the X-A-D's tech, right? So also the cranial nerve that's usually affected in Lyme disease, but it's going to be cranial nerve 7, right? Remember Lyme disease is one of those unusual causes of bilateral Bell's pausing, right? And on MBME exams, Lyme disease is also associated many times with the cardiac complication of AV block, right? Remember Lyme disease on MBME exams can cause a third degree V block because it can involve the presence conduction system in the heart, right? It can involve the presence conduction system in the heart, right? And then it's also kind of high yield to know some other coinfections you can actually get with Lyme disease, right? So what are some other coinfections you can get with Lyme disease? Well, the thing is you can get an aplasmosis, right? You can get an aplasmosis with Lyme disease, right? Remember, basically, people that have an aplasmosis, they'll have like a flu-like illness, right? And they'll have pansideopenia, right?
An aplasmosis, they'll have a, you'll see this new England association, they'll have like a flu-like illness, they'll have pansideopenia, so everything will be low, right? So like they're a white blood cell count to be low, they're red blood cell count to be low, they're platelet count to be low, right? And the way you treat an aplasmosis doesn't matter who you are, you're going to get doxycycline. Every age doesn't matter who you are, you're going to get doxycycline for an aplasmosis. Now, the second coinfection that classically happens with Lyme disease is Babisiosis, right? But the thing is with Babisia, the person is going to have a flu-like illness, but they're going to have a hemolytic anemia. It's very high, you'll know. They're going to have a flu-like illness, but they're going to have a hemolytic anemia. That's how you tell an aplasmosis apart from Babisiosis. An aplasmosis, everything is low, red cell count, white cell count, platelets, all low. But in Babisiosis, the only thing that is low is your hemoglobin, right? It's going to be a hemolytic anemia that those people have, right? So they may even give you a hemoglobin nuria on an exam. This person, obviously in this case, will have a cum's negative hemolytic anemia, right? Because it's not antibodies that are causing the damage. It's Babisia microd, that is causing the damage, right? And remember, for Babisiosis, classically, if you do a blood smear, you're going to find a multi-scross pattern, okay?
You're going to find a multi-scross pattern. This is actually something you want to be able to identify on an exam. So I'll encourage you after you don't listen to this podcast. Just do a quick search. I would encourage you just go look up the multi-scross pattern, burn it into your brain, right? And the way you treat Babisiosis on anemia in exams is that you give a drug combination, going to give you zythromycin, give the two A's, right? You're going to give a zythromycin and that tova-cone, right? You can give a zythromycin and that tova-cone. Remember, a tova-cone is a drug that's many times very good for treating red blood cell infecting organisms, even malaria, right? Some plus modium species respond very nicely to a tova-cone. Usually, you combine that with like progwonia or something like that, right? So remember, this x-adjustic, the fact that it attaches to you doesn't mean you're going to get line disease, right? Remember, you need more than 36 hours of attachment for you to get infection, right? So if they're giving you the question like that timing information, that oh, the take was attached to the present for only like 20 minutes or something like that, you don't need to treat them for line disease. Right? And many times if you have like the classic bauxierache, you can just go ahead and treat them in peritly, right? You can go ahead and treat them in peritly, you don't have to do any kind of diagnostic testing, right?
And remember, a line disease will treat it a different way by age, right? So if you're over the age of eight, we're going to use doxycycline for you, right? But if you're under the age of eight or you're pregnant, the options are different, right? You can use it in a moxicillin, that's very high you to know. Alternatively, you can also use this drug called sephiroxin. Sephiroxin is a cephalosporin that covers line disease very well, right? So, but one thing that's kind of important to know is if a person has like line meningitis, like Lyme disease that has infected the brain, or they have like lymeyocarditis, like Lyme disease that infected a heart, for those people, the drug of choice is going to be IV, sephiroxin. I'll say that again, the drug of choice in those people is going to be IV, sephiroxin, right? And remember, when you're getting doxycycline, this is just a site thing I want to throw in because again, these are things they put on exams. If you're taking doxycycline, remember, you need to avoid the sun, right? So, you don't get sunburns. Remember, doxycycline and other tetracycline's cause-photo sensitivity, right? In fact, it's kind of high you to know the drugs that cause photo sensitivity for purposes of the imping exams. Remember that the pneumonia is sad for photo, right? Sad SAT for photo. The S stands for sulfonamides, the A stands for amyote-ron, and in the T stands for tetracycline's, like doxycycline.
Those drugs you need to avoid the sun in general when you're taking those medications, right? And how could you have prevented this person from getting Lyme disease in the first place? Well, the way you could have prevented them from getting Lyme disease in the first place, right? Is by using like a DEET, right? So DEET, a DEET, like skin repellent or like, you know, clothing that you spray with premissering, right? Clothing that you spray with premissering. Remember, we also use premissering treated as skabies on exams. Okay, so to kind of wrap up this rapid review, the last thing I want to say is, cause there's a common problem that people face on exams. I've kind of talked about it already, but I just want to emphasize it, just give it its own special portion in this podcast, so people can get this stuff down cold, right? So how do you differentiate anaplasmosis from babisiosis and early teiosis on exams, right? So again, for anaplasmosis, remember, anaplasmosis causes pancydopenia. Everything will be low, and this is important because they'll typically, they'll classically write questions and they'll put all these things as answers, and then people are like, how do I differentiate these things? Anaplasmosis causes pancydopenia. Everything is going to be low. The white cells, the red cells, the platelets, they're all going to be low, right? But people that have babisiosis, they have an anemia, that's like the predominant thing. The hemoglobin is going to be low, right?
When every see low hemoglobin in the setting of an infection on anemia in exams, you use an infection disease question, who usually want to think about plus volume species, but a close second, you want to think about this babisia microd, on your exam, right? So babisiosis causes an anemia. Now, on the flip side, early teiosis causes lucopenia, right? So notice, I said anaplasmosis lowers everything, babisiosis lowers the red blood cells, early teiosis lowers your white blood cells, right? So early teiosis causes lucopenia, because the thing is it actually suppresses the production of 200 crores of alpha, so persistent production is almost like you're taking adalimium albomus in a sense, right? So it's a persistent production, right? So many times these people, when they have luciosis, they're also going to have an opportunistic infection at the same time, right? They kind of have an opportunistic like coinfection, like candida, for example, right? And again, remember, we treat early teiosis with doxycycline. We've talked about how we treat anaplasmosis, we said for anaplasmosis, you get doxycycline, for early teiosis, you get doxycycline as well. But for babisiosis, you're going to get easy thromising and atova coin. So I think I'm going to go ahead and stop here.
Again, as I do at the end of every podcast, I do offer one or one tiering for many exams, step one, step two, CK, step three, pre-clinical meds, call exams, 30-ish off exams, and again, also offer review courses for the USMLE step two, so you can step three exams. Again, if you're interested in booking one or one meetings with me, it's something that you don't wait like, oh, divine, can I meet you this weekend, or divine, can I meet you tomorrow? That's going to be largely impossible, right? My schedules get booked out weeks in advance, right? So if you know you want to meet me at a setting time, or you know you have your exam at a setting time, you want to go ahead and reach out to me sooner rather than later, right? Yeah, especially like in the middle of the year, my time is pretty much gone for weeks, right? So many times you have to book with me like a month, sometimes two months ahead, or just some things to keep in mind. And then, if you're a person that's applying for ERAS, again, I've worked with many people that, you know, have had tricky applications, but now I resident, so if you've even filled the USMLE exam, or you have all these red flags, just reach out to me, I can usually advise you on the best way to play your application, especially with personal statements, recommendation letters, your actual ERAS application itself.
So if you're interested in stuff like that, just ship me an email through the website and I'll give you some more information, even more interviews, I think I do with people. And then again, I do have these podcasts on, you know, on at least the most recent 150, on Apple podcasts, on Google podcasts, and on Spotify. So just go on those apps, subscribe to those and you'll get, you'll get those in your post podcast feed. And although if you want every podcast from episode one, all the way to the present episode, which is 334, just go to the website, divancientpodcast.com. Actually, if you're subscribed to that website, when I meet a new podcast, you will get an email notification. And then also on this You Tube channel, divancient, intervention, USMLE podcast and videos, that's where I place my videos. So again, if you subscribe to that website, you'll see all the videos that I've posted and stuff like that. And then finally, many of you listening to this, to these are podcasts, you know that I'm a Christian, right? So I always put life less and I'm actually going to talk about a quick life lesson at the end today. But I do have this, many people have been blessed by those life lessons, I've got tons of emails from people. So I then decided to form another website and another podcast is called divancientlifelessons.com. The podcast itself is called divancient life lessons. So if you go on Apple podcast, that you can find it.
And I, you know, my goal ultimately, the place I want to be is, I want it to be almost like a devotional for people. You don't have to be in medicine. You can be in any other professional career. And they're all going to be less than 10 minutes long, at least that's the goal. And you know, so far I've made 12 episodes and all of them are less than 10 minutes and just talks about our life lesson, just use Bible based teaching to just talk about something that's common in the world today that you need to, you know, kind of watch out for and how to thrive in those circumstances. So the podcast is right now on Apple podcasts and, you know, the website is called divancientlifelessons. And the website is divancientlifelessons.com. So the life lesson I want to share today is the importance of making the right investments, right? The importance of making the right investments. Again, we kind of live in a world, again, you know, for me talk about this drive through mentality business before, you know, many people they want this drive through a person to success, right? You see many people they want to succeed, they want to prosper, they want to do big things with their lives, but they're not willing to make the right investments. They're not willing to put in the dedication that is required, right? So that's something you want to be careful about. Anything good, right? Like there's this thing in Nigeria that if you're eating good soup, it was well prepared by someone, right?
So you can't, you're nothing goes for nothing. If you really want to achieve what has never been achieved before, it needs to be willing to do things that have never been done before, right? Like many of these people that have blased trails in the world we live in today, they've done unusual things, they've made investments, right? Like when you see people become billionaires or you see people get to 80s on the USML Es and they are jealous of them. Don't be jealous. You've not, again, there's no glory without a story, right? There's no glory without a story. So I'll encourage you, if you want something good, you need to invest in it, right? Like for example, if you have kids, you got to take care of them. You can't be a part-time parent. Parenting is sacrifice, but you'll get out of your kids what you're putting to them, right? They are certain there's this show I watch these days are 9911 and you'll see families where the kids are just out of control. Well, but you notice that the parents almost like be lip service to their kids, right? Again, you can, good kids don't just fall down from the sky. No, right? You can pray all you want, you can fast all you want, you can do everything you want, but if you don't actually spend time with your kids and train them, right? Even the Bible says, train up a child in the way you should go when he grows up, you're not the part for it, right? You need to put in investments, you can, you can train your kids from from the chair.
You need to be actively involved in their lives, right? So if you want to do it on the USMLA exams, you can do it on the USMLA exams by hoping to do it on the USMLA exams. You do it on the USMLA exams by getting off your butt, putting in the hard work and you'll get something good from it, especially not just putting in hard work or putting the right kind of work, right? And again, there's so much information out there on the right kind of work to do to perform well on these exams. So again, I'll just encourage you and don't use your background, don't use your background to define how far you will go in life, right? This is something that I really hate personally. Because again, many of you listen to those podcasts, I am an African-American, right? And I remember when I moved to the US, you know, initially, one of the first things that I kept hearing, right, is that, oh, divine, because you're African-American, you're a disenfranchised, and because you're African-American, you're going to have limited opportunities and stuff. That's something that's very common in certain and minority circles. Is there some truth to some of these, in fact, let me not say some truth. Is there a lot of truth to the problems that minorities face? Absolutely, there is, right? But the thing is, again, don't let those, the fact that you're minority, right? In fact, to be honest with you, I don't like using that term on myself, right?
Because again, I feel like I'm a big believer in the power of words, the power of what you speak over yourself, right? The Bible says that death and life and the power of the tongue and the love you will eat its fruit, right? So the thing is, I don't call myself minority, I don't call myself disenfranchised, I don't call myself disadvantaged. No, I don't use those terms because those terms are no good, right? I'm not good. And to be honest with you, when I have kids, I'm not going to drum those messages into their head that they are disadvantaged. No, no, I'm advantage because I have everything to succeed, right? Even the Bible says, great is he is, he is, he is me and he that is in the world, right? I have the hope of glory, I don't have the hope of being disadvantaged, I don't have the hope of being disenfranchised, right? So there's this statement I heard, when I was a few years ago, they should not let your background put your back to the ground, right? So don't let your background define you just for every, again, I almost don't want to use this term, but for every person in certain populations that has not succeeded, there's also people that have don't great work. They also put that of succeed on a high level. Trust me, I'm not just seeing this as an African American, which who thankfully by the grace of God has been successful.
But there are many other African Americans that I've met, many other Latinos, many other Hispanics, many other immigrants that I've met that have been very successful. And don't just say, oh, Nigerians, no, not just Nigerians, people from many other cultures that have been wildly successful, right? Again, the thing that's needed to break through in life, those in look at your skin color, those in look at your blood group. No, no, no, no, right? So don't carry around that. Again, don't get me wrong. Are there problems that have been fixed by the African American population and stuff? I know I'll probably get some heat for this, but it's the truth, right? And this is my podcast. Because for me, I don't want to show a good thing. I want to tell it as it is, right? I did some problems that have been fixed by African Americans and by immigrants and by people from, you know, non-white populations. Absolutely, absolutely. Don't get me wrong. Even I have experienced these things because when I moved to the US, I did living in, you know, I lived in a part of the country that where racism is quite an issue in that part of the country, right? But the thing is, you can break free. You can rise above those things, right? Just put in the work and we go on your side, you can succeed. But please stop carrying that mentality around that you are disadvantaged. The thing is, when you carry that mentality around, you're already setting yourself back before you even started, right?
So don't, don't, don't, don't, don't press that information. I feel like African American parents, you did like pressing that information to their kids. No, don't give your kids that mindset. Give your kids the mindset that they are choosing in generation, that they are peculiar, that they can do great things with their lives, right? If you keep speaking positive into your children's lives and you keep believing positive things about yourself, again, as the Bible says, as a man, think it is hard so he is, right? This is Gribu by James Allen that I read, like more than a decade ago that made a huge impact in my life just on the power of your thoughts, right? How you think about yourself. So I can only encourage you, you know, have the right perspective, think the right thoughts about yourself, or get to work. If you get to work, right? Very soon your testimony will be shared all over the world. So thank you for listening to me. Until next time, God bless you. Thank you.
Practice questions — USMLE style
Question 1 — Infectious Disease
A 35-year-old male plumber presents to the emergency department with a 4-day history of high fever, severe myalgias, and headache. He reports working in an area where sewage runoff was present. On physical examination, he has jaundice and signs of acute kidney injury (creatinine elevated). Laboratory tests reveal elevated liver enzymes (AST/ALT) and thrombocytopenia. The patient's exposure history strongly suggests contamination with animal urine or dirty water. Which organism is the most likely cause of this illness?
- A) Borrelia burgdorferi
- B) Rickettsia rickettsii
- C) Leptospira interrogans
- D) Brucella abortus
Answer: C. The clinical picture—fever, myalgias, jaundice, and acute kidney injury following exposure to contaminated water or animal urine (especially in a plumber)—is classic for leptospirosis. Leptospira interrogans is the causative agent. Diagnosis often involves an ELISA looking for IgM antibodies, followed by confirmation with microscopic agglutination testing. Treatment typically requires doxycycline or penicillin/ceftriaxone.
Question 2 — Infectious Disease
A 27-year-old hiker presents to a clinic after spending time in New England. He reports developing a rash and has been experiencing flu-like symptoms, including fever and fatigue. Laboratory workup reveals pancytopenia (low white blood cell count, low red blood cell count, and low platelet count). The physician suspects an infection acquired from local wildlife exposure. Which of the following conditions is most likely responsible for this specific pattern of cytopenias?
- A) Babesiosis
- B) Ehrlichiosis
- C) Anaplasmosis
- D) Lyme disease
Answer: C. Anaplasmosis, caused by Anaplasma phagocytophilum, characteristically leads to pancytopenia (low counts across all three cell lines). In contrast, Babesiosis typically causes hemolytic anemia (low RB Cs), and Ehrlichiosis usually presents with leukopenia. While Lyme disease itself can cause various issues, the specific finding of pancytopenia points strongly toward Anaplasmosis among these choices.
Question 3 — Metabolic Disorder
A neonate is diagnosed with a lysosomal storage disorder. The child presents with progressive neurological decline, hypotonia, and developmental regression. Physical examination reveals a cherry-red spot on the macula. Initial workup suggests a deficiency in an enzyme critical for lipid metabolism. Further testing indicates that the accumulation of sphingolipids primarily affects macrophages within the reticuloendothelial system (spleen/liver). Which specific disorder is most likely responsible, given the combination of neurological symptoms and hepatosplenomegaly?
- A) Tay-Sachs disease
- B) Niemann-Pick disease
- C) Gaucher disease
- D) Zellweger syndrome
Answer: B. The key differentiating feature provided in the scenario—hepatosplenomegaly combined with a cherry-red spot and sphingolipid accumulation affecting macrophages of the reticuloendothelial system—is characteristic of Niemann-Pick disease. Tay-Sachs disease, while also causing neurodegeneration and a cherry-red spot, typically does not involve significant hepatosplenomegaly.
Question 4 — Metabolic Disorder
A two-year-old female is brought to the clinic by her parents due to progressive vision loss, hearing impairment, and generalized hypotonia over several months. Laboratory testing reveals markedly elevated levels of very long-chain fatty acids (VLCF As) in her plasma. Genetic analysis suggests a defect in peroxisomal function. What is the most likely diagnosis?
- A) Alpha-1 antitrypsin deficiency
- B) Niemann-Pick disease
- C) Zellweger syndrome
- D) Adrenoleukodystrophy
Answer: C. The combination of progressive neurological decline, hypotonia, and elevated VLCF As points to a peroxisomal disorder. Zellweger syndrome is the most severe form of peroxisome biogenesis disorders (PB Ds), resulting in impaired breakdown of very long-chain fatty acids because the necessary enzymes are not properly localized or functional within the peroxisomes.
Quick fire review
What is the primary metabolic defect in Tay-Sachs disease?
Deficiency of Hexosaminidase A, leading to GM2 ganglioside buildup.
Which lysosomal storage disorder classically presents with hepatosplenomegaly?
Niemann-Pick disease (due to Sphingomyelinase deficiency).
What is the key differentiating finding between Tay-Sachs and Niemann-Pick on exam?
Hepatosplenomegaly suggests Niemann-Pick; absence of this in Tay-Sachs.
Which disorder involves a defect in peroxisomal function, leading to VLCFA accumulation?
Zellweger syndrome (PEX gene mutation).
What is the classic triad associated with Lyme disease coinfections that cause pancytopenia?
Anaplasmosis/Ehrlichiosis.
Which specific finding on a blood smear suggests Babesiosis infection?
Multi-spore pattern.
What are the three high-yield spirochetes to remember for USMLE exams?
Leptospira, Borrelia (Lyme), and Treponema pallidum (Syphilis).
Which populations are classically associated with Tay-Sachs disease on board exams?
Ashkenazi Jewish, French Canadian, or Cajun communities.
What is the primary mechanism of injury in Zellweger syndrome?
Failure to break down very long-chain fatty acids (VLCF As) due to peroxisomal dysfunction.
Name three drugs that cause photosensitivity and require sun avoidance.
Sulfonamides, Aminoglycosides, and Tetracyclines (e.g., Doxycycline).
What is the most critical difference between Aplasmosiosis and Babesiosis?
Aplasmosiosis causes pancytopenia (all cell lines low); Babesiosis primarily causes hemolytic anemia (low hemoglobin).
If a patient has Lyme disease, what cranial nerve can be affected, and what cardiac complication should be suspected?
CN VII (Bell's palsy) and AV block/Third-degree heart block.
What is the preferred drug for treating severe CNS or cardiac manifestations of Lyme disease?
IV Ceftriaxone or IV Cefuroxime (IV cephalosporin).
Quick recall / Anki-style questions
Which populations are classically associated with Tay-Sachs disease on board exams?
Ashkenazi Jewish, French Canadian, or Cajun communities.
What is the primary mechanism of injury in Zellweger syndrome?
Failure to break down very long-chain fatty acids (VLCF As) due to peroxisomal dysfunction.
Name three drugs that cause photosensitivity and require sun avoidance.
Sulfonamides, Aminoglycosides, and Tetracyclines (e.g., Doxycycline).
What is the most critical difference between Aplasmosiosis and Babesiosis?
Aplasmosiosis causes pancytopenia (all cell lines low); Babesiosis primarily causes hemolytic anemia (low hemoglobin).
If a patient has Lyme disease, what cranial nerve can be affected, and what cardiac complication should be suspected?
CN VII (Bell's palsy) and AV block/Third-degree heart block.
What is the preferred drug for treating severe CNS or cardiac manifestations of Lyme disease?
IV Ceftriaxone or IV Cefuroxime (IV cephalosporin).