Lymphogranuloma venereum: what does the clinician need to know? Rectal biopsy showed severe non-specific inflammation and the patient was treated empirically with steroid suppositories for possible irritable bowel disease. Following genitourinary medicine review, a rectal swab specimen tested positive for Chlamydia trachomatis, subsequently typed as the L2 strain. Symptoms abated completely after three weeks' treatment with doxycycline.syndrome including anogenital ulceration and buboes (Fig 3). Less common presentations have been described such as urethritis 6 and bubonulus 7 (primary stage of disease with large tender lymphangial nodule and lymphangitis of dorsal penis). Asymptomatic rectal infections have been detected only rarely within a large casefinding exercise in the UK, suggesting that a large reservoir of 'silent' infection is unlikely. 8
Differential diagnosisThe differential diagnosis of proctitis among homosexual men includes rectal gonorrhoea, which is usually less severe clinically and often asymptomatic. Anorectal herpes simplex virus-1 or -2 infection, especially if a primary infection, can cause severe anorectal pain often out of proportion to other proctitis symptoms and may also cause regional neurological symptoms including urinary retention and constipation. Non-LGV rectal C. trachomatis infection caused by serovars D-K is usually asymptomatic but can occasionally show clinical features of overt proctitis. Syphilis infection is on the rise again among homosexual men, and in its role as 'the great imitator' can cause clinical proctitis.Excellent clinical and microbiological responses have been observed in LGV infection with the recommended treatment of oral doxycycline 100 mg bid for three weeks. 9,10
Laboratory diagnosisThe
Detection of lymphogranuloma venereum in rectal specimensIn October 2004, the Sexually Transmitted Bacteria Reference Laboratory (STBRL) at the Health Protection Agency (HPA) Centre for Infections established a testing algorithm for the detection of LGV in rectal specimens. This includes confirmation of the presence of C. trachomatis using a real-time polymerase chain reaction (RT-PCR) that uses primers different from any commercial assay. 11 Residual samples from both NAATs and EIAs or dry swabs can be tested. Any specimens giving a negative result are confirmed using the Qiagen RT-PCR (which is not used extensively in the UK) and a report issued. All samples confirmed to contain C. trachomatis-specific DNA are then tested to determine whether this belongs to an LGV serovar (L1, L2 or L3), using an RT-PCR which detects a deletion in the pmp gene present only in L-serovars of C. trachomatis. 12 This test gives a positive result for LGV-associated serovars and a negative result for other serovars and provides a timely result allowing a positive report to be issued. All positive specimens are then confirmed using a nested PCR that amplifies the omp1 gene which is present in single copy, followed by digestion with restriction endonucleases. 13,14 The pattern obtained is ...