furuncles

A furuncle begins as folliculitis and deepens into a walled-off collection of pus. It appears in hair-bearing, friction-prone, sweaty areas: face, neck, axilla, buttocks, and thighs. The cardinal management principle is that an abscess requires drainage; for a simple, small furuncle in an immunocompetent patient without cellulitis or systemic signs, incision and drainage alone is often sufficient, and antibiotics are added for larger or multiple lesions, surrounding cellulitis, systemic features, immunosuppression, or a high-risk site such as the face. Because community-acquired MRSA is now common and often carries Panton-Valentine leukocidin, empirical cover should include trimethoprim-sulfamethoxazole, doxycycline, or clindamycin rather than a plain beta-lactam. Recurrent furunculosis suggests persistent nasal or perineal carriage and merits decolonization, and should also prompt consideration of diabetes, HIV, and, in children with cold abscesses and eczema, hyper-IgE (Job) syndrome. Hidradenitis suppurativa is a differential in the axilla and groin and is not primarily infectious.