1/
Let's learn bout a condition that affects > 95% of the world's population.
Note I said learn not just memorize a list of symptoms/signs.
Let's learn bout a condition that affects > 95% of the world's population.
Note I said learn not just memorize a list of symptoms/signs.
2/
Learning medicine in the context of patients hits way differently than just reading a book to pass a test.
Why?
The stimulus to learn is way greater. The stakes are much higher. You won't leave any stone unturned. And you'll remember the salient features forever.
Learning medicine in the context of patients hits way differently than just reading a book to pass a test.
Why?
The stimulus to learn is way greater. The stakes are much higher. You won't leave any stone unturned. And you'll remember the salient features forever.
3/
He was 39 years old. He no longer had the energy to walk the 4km to work. His throat hurt whenever he swallowed. At night he had to change his sweat-drenched shirt. He felt a few bumps in his neck. He was frightened. His symptoms worsened day by day.
He was 39 years old. He no longer had the energy to walk the 4km to work. His throat hurt whenever he swallowed. At night he had to change his sweat-drenched shirt. He felt a few bumps in his neck. He was frightened. His symptoms worsened day by day.
4/
He went to the ED and waited 10 hours to be seen. His vitals were normal as were his CBC and BMP. Rapid strep test was negative as was his mono spot test. He was prescribed Augmentin and told to see his primary care doctor.
He went to the ED and waited 10 hours to be seen. His vitals were normal as were his CBC and BMP. Rapid strep test was negative as was his mono spot test. He was prescribed Augmentin and told to see his primary care doctor.
5/
A few doses later, he broke out into a macular and papular rash. What is the dx?
A few doses later, he broke out into a macular and papular rash. What is the dx?
6/
Serology confirmed dx of EBV+ mono.
This is where the fun begins. Let's really learn mono.
Understanding, not memorizing a disease, starts with learning its pathophysiology.
>90% of us have been infected with/ EBV by age 30.
Serology confirmed dx of EBV+ mono.
This is where the fun begins. Let's really learn mono.
Understanding, not memorizing a disease, starts with learning its pathophysiology.
>90% of us have been infected with/ EBV by age 30.
7/
Called the kissing disease b/c most often transmitted via saliva during deep kissing.
Someone, may be asymptomatic, with oral shedding of EBV kisses an EBV-naive person.
The EBV infects the B-LYMPHOCYTES in the oral cavity. This activates the T-LYMPHOCYTES.
Called the kissing disease b/c most often transmitted via saliva during deep kissing.
Someone, may be asymptomatic, with oral shedding of EBV kisses an EBV-naive person.
The EBV infects the B-LYMPHOCYTES in the oral cavity. This activates the T-LYMPHOCYTES.
8/
Just knowing this fact you can explain so much.
🫵Often pt w/ increased lymphocytes (absolute and/or percentage) and/or atypical-looking lymphocytes on smear
🫵Entry point is the oral cavity - commonly leading to pharyngitis and swollen lymph nodes of the head/neck.
Just knowing this fact you can explain so much.
🫵Often pt w/ increased lymphocytes (absolute and/or percentage) and/or atypical-looking lymphocytes on smear
🫵Entry point is the oral cavity - commonly leading to pharyngitis and swollen lymph nodes of the head/neck.
9/
The virus lives in our memory B cells FOREVER. May have asymptomatic shedding from time to time or it may reactivate during intense immune stimulation.
Don't be quick to blame EBV even if PCR is positive in your hospitalized patients. More on this in a later tweet.
The virus lives in our memory B cells FOREVER. May have asymptomatic shedding from time to time or it may reactivate during intense immune stimulation.
Don't be quick to blame EBV even if PCR is positive in your hospitalized patients. More on this in a later tweet.
10/
Almost all patients have fatigue, fever, and head/neck lymphadenopathy.
Majority w/ night sweats and pharyngitis.
The pathophysiology of sweats is fascinating but let's leave that for another time.
Almost all patients have fatigue, fever, and head/neck lymphadenopathy.
Majority w/ night sweats and pharyngitis.
The pathophysiology of sweats is fascinating but let's leave that for another time.
11/
Our patient had fatigue, sweats, lymphadenopathy, and pharyngitis.
The right frame is critical in diagnosis.
Your mind should convert this into INFECTIOUS MONONUCLEOSIS (IM).
Our patient had fatigue, sweats, lymphadenopathy, and pharyngitis.
The right frame is critical in diagnosis.
Your mind should convert this into INFECTIOUS MONONUCLEOSIS (IM).
12/
EBV is NOT the only cause of IM. Think of its cousins HIV and CMV. Anytime you consider one of these the others should be considered too (HEC yea! aka HIV, EBV, CMV). Toxo can do it too.
Mimics include lymphoma, drugs, and PNC-sens pharyngitis (GAS, fusobacterium, etc).
EBV is NOT the only cause of IM. Think of its cousins HIV and CMV. Anytime you consider one of these the others should be considered too (HEC yea! aka HIV, EBV, CMV). Toxo can do it too.
Mimics include lymphoma, drugs, and PNC-sens pharyngitis (GAS, fusobacterium, etc).
13/
The first step in our patient's diagnosis required the frame of IM.
90% of the time IM is d/t EBV. But must strongly consider HIV.
The first step in our patient's diagnosis required the frame of IM.
90% of the time IM is d/t EBV. But must strongly consider HIV.
14/
Summary so far
🫵EBV often transmitted via saliva
🫵It infects lymphocytes - look for increased or atypical lymphocytes so CBC w/ diff and smear is important!
🫵Most common cause of IM but don't forget HIV/CMV
Summary so far
🫵EBV often transmitted via saliva
🫵It infects lymphocytes - look for increased or atypical lymphocytes so CBC w/ diff and smear is important!
🫵Most common cause of IM but don't forget HIV/CMV
15/
Our patient's rash to PNC-abx makes EBV the most likely diagnosis.
Something about EBV leads to a transient hypersensitivity reaction to PNC during acute illness. Most tolerate PNC-abx in the future. Not a permanent allergy.
Our patient's rash to PNC-abx makes EBV the most likely diagnosis.
Something about EBV leads to a transient hypersensitivity reaction to PNC during acute illness. Most tolerate PNC-abx in the future. Not a permanent allergy.
16/
Monospot neg in 10% of patients. False + w/ acute HIV can happen.
Viral capsid antigen ab is best test for acute EBV in immunocompetent host. IgM points to acute infection. Literally ab to the to outer surface of EBV.
EBNA antigen IgG r/o acute EBV, confirms past exposure
Monospot neg in 10% of patients. False + w/ acute HIV can happen.
Viral capsid antigen ab is best test for acute EBV in immunocompetent host. IgM points to acute infection. Literally ab to the to outer surface of EBV.
EBNA antigen IgG r/o acute EBV, confirms past exposure
17/
Let's apply cognitive autopsy to our pt.
🫵He had IM
🫵Prob best next tests would be CBC w/ diff (lymphocytes)/smear, LFTs, rapid strep test/Cx, mono spot, and HIV ab/ag
🫵His debilitating fatigue/night sweats favored IM over bacterial pharyngitis
Let's apply cognitive autopsy to our pt.
🫵He had IM
🫵Prob best next tests would be CBC w/ diff (lymphocytes)/smear, LFTs, rapid strep test/Cx, mono spot, and HIV ab/ag
🫵His debilitating fatigue/night sweats favored IM over bacterial pharyngitis
18/
Medicine is all about probability. Note the use of "likely" and "probably." We never know for sure. The patient's response to treatment should be viewed as another diagnostic test. He developed a rash to PNC further supporting EBV + mono.
Medicine is all about probability. Note the use of "likely" and "probably." We never know for sure. The patient's response to treatment should be viewed as another diagnostic test. He developed a rash to PNC further supporting EBV + mono.
19/
You'll love medicine the more you understand it. Yes, it takes time. But the return on your investment makes it all worth it.
Enjoy this figure by me and my brother @rabihmgeha
You'll love medicine the more you understand it. Yes, it takes time. But the return on your investment makes it all worth it.
Enjoy this figure by me and my brother @rabihmgeha
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