Chlamydia trachomatis causes trachoma (serovars A–C) and sexually transmitted disease (serovars D–K). Lymphogranuloma venereum (LGV) is caused by serovars L1, L2, L3. LGV classically differs from other urogenital Chlamydia infections by:

• A Producing a small painful vesicle that heals spontaneously
• B Causing urethritis with large gram-negative diplococci in PMNs
• C Causing inguinal and femoral lymphadenopathy (buboes) crossing Poupart's ligament creating the groove sign ✓
• D Producing a chancre with induration and painless ulcer

Explanation

Lymphogranuloma venereum (LGV, serovars L1–L3) follows three stages: primary small painless papule/ulcer, secondary stage with painful inguinal and femoral lymphadenopathy (buboes) separated by Poupart's (inguinal) ligament creating the pathognomonic 'groove sign' (Greenblatt's sign), and tertiary stage causing genital elephantiasis and rectal strictures. LGV serovars invade deep lymphoid tissue (unlike D–K serovars that are epitheliotropic). A painful vesicle describes HSV-2 (primary). Gram-negative diplococci in PMNs is gonorrhoea. A painless indurated ulcer describes primary syphilis (chancre). Treatment is doxycycline 100 mg BD for 21 days.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.