A 25-year-old woman presents with painless unilateral inguinal lymphadenopathy that becomes fluctuant (bubo). She reports a healed painless genital ulcer 3 weeks ago. LGV complement fixation titre is 1:64. The responsible Chlamydia trachomatis serovars are:

• A Serovars A, B, C (trachoma serovars)
• B Serovars L1, L2, L2a, L3 (LGV serovars) ✓
• C Serovars D–K (genital serovars)
• D Serovar L2b only (recently recognized pandemic strain)

Explanation

Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis serovars L1, L2, L2a, and L3, which are more invasive than genital serovars (D-K) as they can invade and replicate in mononuclear phagocytes and spread to lymph nodes. Serovars A/B/C cause ocular trachoma and D-K cause genital chlamydiosis (NGU, cervicitis). The Frei test (intradermal test, now obsolete) was historically used for LGV. Doxycycline for 21 days is the treatment.

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.