Patient present in your clink. On physical examination, there is bilateral lymphadenopthy, which is tender on palpation. He gave history of sexual contact. He is truck driver by profession. The probable causative agent is:
**Core Concept**
The underlying principle being tested is the identification of a probable causative agent for a patient presenting with bilateral lymphadenopathy, which is tender on palpation, and a history of sexual contact. This scenario suggests a sexually transmitted infection (STI). The patient's profession as a truck driver may increase his risk for such infections due to mobility and potential for multiple sexual contacts.
**Why the Correct Answer is Right**
Given the context of sexual contact and the symptom of tender bilateral lymphadenopathy, the most likely diagnosis is lymphogranuloma venereum (LGV), which is caused by **Chlamydia trachomatis** serovars L1, L2, or L3. LGV is characterized by its ability to cause lymphadenopathy, which is often tender, and its association with sexual transmission.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option provided, it's challenging to give a precise reason for its incorrectness, but if it were a common STI not typically associated with lymphadenopathy, such as gonorrhea, it would be incorrect.
**Option B:** Similarly, without the specific option, if it were an agent not commonly associated with sexual transmission or lymphadenopathy, it would be incorrect.
**Option C:** If this option were an agent like **Treponema pallidum** (syphilis), while syphilis can cause lymphadenopathy, the context provided (tender lymphadenopathy and specific mention of sexual contact) more strongly suggests LGV.
**Option D:** If this option were an agent not associated with STIs or lymphadenopathy, it would clearly be incorrect.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that lymphogranuloma venereum (LGV) is a significant cause of lymphadenopathy in the context of sexual transmission, particularly in individuals with high-risk sexual behaviors. The tender nature of the lymphadenopathy is a distinguishing feature.
**Correct Answer:** Correct Answer: D. Chlamydia trachomatis.