Antibiotics: Jarisch-Herxheimer reaction: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pharmacology · Antibiotics: Jarisch-Herxheimer reaction

Sample item

Four hours after a first dose of benzathine penicillin for secondary syphilis, a man develops fever, chills, myalgia and accentuation of his rash. There is no wheeze, urticaria or hypotension. What is the best management?

AStop treatment since this is a drug allergyBStop penicillin and give intramuscular adrenalineCSwitch to doxycycline and add prednisoloneDContinue penicillin and give antipyretics with supportive care

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Continue penicillin and give antipyretics with supportive care

This is the Jarisch-Herxheimer reaction, caused by cytokine release (TNF-alpha, IL-6) as large numbers of spirochaetes die. It appears within hours, resolves in 24 hours and is not an allergy. Treatment is symptomatic and the penicillin course is continued.

Option by option

A. Stop treatment since this is a drug allergy
It is not an allergic reaction, and stopping would leave the infection untreated.
B. Stop penicillin and give intramuscular adrenaline
Adrenaline is for anaphylaxis, and there are no features of it here.
C. Switch to doxycycline and add prednisolone
Changing the drug is unnecessary and the reaction would occur with any effective treponemicidal drug.
D. Continue penicillin and give antipyretics with supportive care (correct)
Correct. The reaction is self-limiting and is managed symptomatically while treatment continues.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is D, Continue penicillin and give antipyretics with supportive care. This is the Jarisch-Herxheimer reaction, caused by cytokine release (TNF-alpha, IL-6) as large numbers of spirochaetes die.

Why is "Stop treatment since this is a drug allergy" not the answer?

It is not an allergic reaction, and stopping would leave the infection untreated.

Why is "Stop penicillin and give intramuscular adrenaline" not the answer?

Adrenaline is for anaphylaxis, and there are no features of it here.

Why is "Switch to doxycycline and add prednisolone" not the answer?

Changing the drug is unnecessary and the reaction would occur with any effective treponemicidal drug.

What concept does this question test?

It tests Antibiotics: Jarisch-Herxheimer reaction in Pharmacology. It appears within hours, resolves in 24 hours and is not an allergy. Treatment is symptomatic and the penicillin course is continued.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Antibiotics: Jarisch-Herxheimer reaction?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.