HSV-associated proctitis presenting without perianal lesions: why testing and empirical treatment may be important.

A man in his late 30s presented with a several-day history of rectal pain, discharge and bleeding associated with systemic upset. Sexual history revealed receptive anal sex with several male partners in the 2 weeks preceding his clinic visit. Examination of the perianal area was unremarkable. Proctoscopy showed evidence of non-ulcerative proctitis. Microscopy for Gram stain showed pus cells plus extracellular Gram-negative diplococci. The patient was treated for presumptive gonorrhoea and chlamydial infection with ceftriaxone, azithromycin and doxycycline. The patient failed to improve with this treatment regimen. Rectal swab results at 48 hours confirmed the causative agent to be herpes simplex virus (HSV) type 2. The patient was recalled and treated successfully with valaciclovir. This case serves as a useful reminder to clinicians to consider HSV in the differential diagnosis of sexually transmitted proctitis, in the absence of perianal or anorectal ulceration.