Perianal streptococcal dermatitis in adults: its association with pruritic anorectal diseases is mainly caused by group B Streptococci

Aim Although perianal streptococcal dermatitis (PSD) is well known in children, it has only rarely been documented in adults. The incidence and necessity for treatment may be underestimated. We have retrospectively identified adult patients with perianal streptococcal dermatitis. Method Patients with streptococcal anal dermatitis were identified from a prospective office database. Treatment was with oral antibiotics according to the organism sensitivity. Additional concomitant anorectal disease was treated according to standard guidelines. Patients were compared with a control group, without eczema or erythema, for the presence of -haemolysing Streptococci on perianal swab. Demographic and microbiological data were assessed and compared between and within treatment and control groups. Results Fifty-three (22 female) patients older than 20 (mean=49) years of age were diagnosed with perianal streptococcal dermatitis between 2005 and 2009. In most cases group B -haemolytic Streptococci were found. Fifty patients received antibiotics for 14days. In 28 of 33 patients who had a post-treatment swab, the result was negative. Five patients showed Streptococci of different groups in the post-treatment swab. Of the 50 patients, 21 (42%) had no further anorectal complaint and 29 (58%) required continuing treatment for another anorectal condition. In the control group -haemolysing Streptococcus was found in 34%. Men over 60years of age more often required no further anorectal treatment compared with women (P<0.05). Conclusion Perianal streptococcal dermatitis occurs in adult patients more often than reported. It is mainly caused by group B -haemolysing Streptococcus. Its diagnosis is important because it can cause serious systemic infections, especially in the elderly and in newborns. Antibiotics resolve the condition in a high proportion of patients.