A man presents with a tender unilateral inguinal mass with overlying erythema. The mass fluctuates and the overlying skin shows a groove sign (groove between two groups of nodes separated by Poupart's ligament). He has no genital ulcer currently. The diagnosis and causative organism are:

• A Lymphogranuloma venereum (LGV) — Chlamydia trachomatis serovars L1, L2, L3 ✓
• B Chancroid — Haemophilus ducreyi
• C Donovanosis (granuloma inguinale) — Klebsiella granulomatis
• D Herpes simplex — HSV-2

Explanation

The groove sign of Greenblatt — a groove in the inguinal region separating superior (inguinal) and inferior (femoral) nodes by Poupart's ligament — is pathognomonic of Lymphogranuloma venereum (LGV). LGV is caused by Chlamydia trachomatis serovars L1, L2 (most common), and L3. The primary lesion (small painless ulcer/papule) is often missed; buboes (fluctuant inguinal lymphadenopathy) represent the secondary stage. Chancroid causes painful ulcers with soft, tender unilateral lymphadenopathy but without the groove sign. Donovanosis causes painless progressive ulcers without lymphadenopathy.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.