Friday, August 14, 2009


You are a third year medical student doing a standard H&P on a healthy 50 year old man in family practice. He's here for an annual check-up. He has no complaints. His past medical history is significant for hypertension, GERD, an appendectomy at age 22, peptic ulcer disease s/p treatment with amoxicillin, clarithromycin, and omeprazole, and syphilis treated with PCN 10 years ago. His current medications are metoprolol and a multivitamin. He's allergic to penicillin; he said when he got it 10 years ago, he had fever, headache, myalgia, rash about 1-2 hours after taking it, peaking at 8 hours, and resolving within 2 days. His family history is significant for depression, hypertension, and mother with breast cancer at age 60. He drinks occasionally, smoke 1/2 ppd x30 years, and denies IVDU. He works as a mechanic, lives with his wife and two kids. His review of systems is negative.

Challenge: When you present this history to your preceptor, he says, "I bet he doesn't really have a penicillin allergy." Interesting! Why does he say that?


Stephanie said...

jarisch-herxheimer rxn after pcn tx for syphilis...thought to be the body's reaction to so many antigens being spilled out by the bacteria being killed by pcn.

Alex said...

jarisch-herxheimer (sp?) rxn

shabnam said...

Jarisch-Herxheimer reaction

What the patient perceived as penicillin allergy was probably Jarisch-Herxheimer Reaction...The reaction occurs due to the release of a large quantity of toxins when bacteria die in the body as a result of rapid antibiotic therapy(especially notable with Spirochaetes as in syphilis and Lymes disease)

Craig Chen said...

wow! Nicely done! I'm v. impressed.

Treatment of syphilis with penicillin can lead to a Jarisch-Herxheimer reaction, the acute febrile reaction described here due to release of treponemal lipopolysaccharide from dying spirochetes.

Source: UpToDate.