Background Chlamydial inclusion conjunctivitis caused by genital serovars of Chlamydia trachomatis (CT) is well-recognised, and usually thought to result from auto-inoculation from genital CT infection or direct sexual contact. In this case series we review nine patients with co-existing pharyngeal and conjunctival CT infection and hypothesise on the relationship between the two conditions.

Methods Retrospective analysis of 9 patients with pharyngeal and conjunctival CT infection. Diagnoses were made based on clinical findings and the detection of CT RNA by the Aptima Combo2 assay (Gen-Probe).

Results We found 9 cases of coexisting pharyngeal and conjunctival infection in men: 8 were men who have sex with men (MSM) and 1 was heterosexual. All but one MSM had participated in both receptive and insertive oral sex, with the final patient reporting insertive oral sex and rimming.

All patients were symptomatic with unilateral conjunctivitis; one had symptoms bilaterally. Four of the 9 patients had a normal anogenital examination, and only 1 patient had a sore throat. Six of nine patients also had rectal CT infection, with 1 equivocal rectal CT result. Only two patients had co-existing urethral CT infection. Two patients had solely pharyngeal CT, including the heterosexual man.

Conclusions Whilst traditionally thought to be a result of auto-inoculation from genital CT infection, we speculate that pharyngeal CT infection might be a more common source, or even a sequela, of CT conjunctivitis - at least in MSM. Alternatively, CT detected in the throat might be secondary to drainage of lacrimal fluid from a CT-infected eye. As CT conjunctivitis might be treated in isolation without comprehensive CT screening, or at most, with genital CT screening alone, we feel pharyngeal CT testing is indicated in all patients with CT conjunctivitis. The role of the nasolacrimal duct as a potential two-way conduit of infection requires further investigation.