A patient suffering from syphilis is given penicillin. He may develop
**Core Concept**
The patient's reaction to penicillin is due to the Jarisch-Herxheimer reaction, a common phenomenon observed in patients with syphilis who undergo treatment with penicillin. This reaction is caused by the sudden release of endotoxins from the dying bacteria, leading to a systemic inflammatory response.
**Why the Correct Answer is Right**
The Jarisch-Herxheimer reaction typically occurs within the first 24 hours after initiating penicillin therapy for syphilis. It is characterized by the sudden onset of symptoms such as fever, chills, and a worsening of the skin rash. This reaction is thought to be caused by the release of lipopolysaccharides from the bacterial cell walls, which stimulate the immune system to produce pro-inflammatory cytokines. The reaction is usually self-limiting and resolves within 24 hours, but it can be severe in some cases.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is not a known side effect of penicillin in syphilis treatment. While penicillin can cause allergic reactions, the Jarisch-Herxheimer reaction is a specific phenomenon related to the treatment of syphilis.
* **Option B:** This is not a characteristic of the Jarisch-Herxheimer reaction. While patients may experience fever and chills, the reaction is not typically associated with a worsening of the skin rash.
* **Option C:** This is not a known side effect of penicillin in syphilis treatment. While penicillin can cause gastrointestinal side effects, the Jarisch-Herxheimer reaction is a specific phenomenon related to the treatment of syphilis.
**Clinical Pearl / High-Yield Fact**
To remember the Jarisch-Herxheimer reaction, recall that it occurs within the first 24 hours after initiating penicillin therapy for syphilis and is characterized by symptoms such as fever, chills, and a worsening of the skin rash. This reaction is a common phenomenon in patients with syphilis who undergo treatment with penicillin.
**Correct Answer:** B.