The ABCs of Perineal Streptococcal Dermatitis.

Perineal streptococcal dermatitis (PSD) is largely known to be caused by group A β-hemolytic Streptococcus (GAS). We would like to bring cases of non-GAS PSD to the attention of dermatologists, as there are implications for workup and therapy. We report 3 pediatric cases of PSD: 1 caused by GAS, 1 caused by group B β-hemolytic Streptococcus (GBS), and 1 associated with group C β-hemolytic Streptococcus (GCS). GBS and GCS are very rarely reported in pediatric cases of PSD. The literature on non-GAS PSD is reviewed, which additionally revealed several instances of PSD caused by group G β-hemolytic Streptococcus (GGS) and Staphylococcus aureus. GBS, GCS, GGS, and S aureus are significant causes of PSD to consider, particularly among adult patients, based on our encountered cases and the literature. If using rapid antigen tests to expedite the diagnosis of GAS, we recommend supplementing with a lesional swab for bacterial culture and sensitivity as the rapid antigen test does not detect non-GAS organisms. Therapy should be tailored to the microbiologic cause.