Sexually transmitted infections manifesting as proctitis

Abstract

There is a rising incidence of several sexually transmitted infections (STIs), many of which can present with proctitis. Causative organisms include Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus, Treponema pallidum (syphilis), Giardia lamblia (giardiasis) and Entamoeba histolytica (amoebiasis). This paper outlines important clinical discriminators and key investigations to distinguish these organisms from non-infective pathology that include inflammatory bowel disease, solitary rectal ulcer syndrome and Behçet's syndrome. Management of these infections is described and suggestions are made for successful gastroenterology clinical consultation when an STI is suspected.

Keywords: Crohn's Disease; Infective Colitis; Inflammatory Bowel Disease; Parasitic Diseases; Ulcerative Colitis.

Figure 1

Solitary syphilitic chancre affecting (a) male and (b) female external genitalia. A chancre is the archetypal feature of primary syphilis. These ulcers are classically anogenital, solitary, indurated and painless; however, in atypical cases they may be multiple and painful, and can occur at extra-anogenital sites.

Figure 2

Palmoplantar rash in secondary syphilis. The skin eruption associated with secondary syphilis characteristically has a palmoplantar distribution, is pink or dark red and not pruritic.

Figure 3

Perianal inspection (question 2).

Figure 4

Gram stain of swab exudate (question 4).

Figure 5

Gram stain of swab exudate (answer 4). Arrows point towards neutrophils containing intracellular Gram-negative diplococci.