Paper II
Question
Lymphogranuloma venereum.
Answer
Lymphogranuloma venereum (LGV): a sexually transmitted infection caused by Chlamydia trachomatis serovars L1, L2, and L3 (distinct from the serovars causing genital tract infection (D-K) and trachoma (A-C)).
Clinical features: progresses through three stages —
- Primary stage: a small, transient, often unnoticed painless genital papule/ulcer at the site of inoculation, which heals spontaneously.
- Secondary stage: painful, tender, matted inguinal and/or femoral lymphadenopathy (buboes), which may suppurate and form draining sinus tracts (the “groove sign” — enlarged lymph nodes above and below the inguinal ligament — is a classical though not universal finding); may be accompanied by fever and systemic symptoms.
- Tertiary stage: chronic complications including genital elephantiasis, rectal strictures, and fistulae, particularly in untreated/longstanding infection, more common with rectal LGV.
Laboratory diagnosis:
- Nucleic Acid Amplification Test (NAAT)/PCR — the preferred, most sensitive method, detecting C. trachomatis DNA from bubo aspirate, ulcer swab, or rectal swab, with specific genotyping to confirm LGV serovars (L1-L3) where needed.
- Serology (complement fixation test/microimmunofluorescence) — high antibody titres support the diagnosis, particularly useful given the often transient/subclinical primary lesion.
- Culture — technically demanding (requires cell culture, as Chlamydia is an obligate intracellular organism), not routinely used.
- Aspiration of bubo for direct examination/NAAT, avoiding incision and drainage which can lead to chronic sinus formation.
Treatment: Doxycycline (a prolonged 21-day course), or Azithromycin as an alternative.