Furunculosis

Furunculosis is a skin infection characterized by painful nodules called furuncles (boils) that arise from infection of hair follicles and surrounding tissue. It most often results from Staphylococcus aureus, including methicillin-resistant strains (MRSA), and may occur with nasal carriage of the organism. A furuncle is a single abscess, while clustered lesions can form a carbuncle.

Clinical features typically include tender, erythematous nodules that progress to fluctuant abscesses with purulent drainage. They commonly occur on the neck, face, axillae, and buttocks. Fever and malaise may accompany more extensive disease. Recurrent furunculosis is common in some individuals.

Diagnosis is usually clinical. Culturing the drained pus or exudate can guide antibiotic therapy, especially in recurrent infections or suspected MRSA. Distinguish furunculosis from cellulitis or simple folliculitis; deeper or orbital involvement or systemic symptoms may require imaging or laboratory tests.

Treatment centers on incision and drainage of localized furuncles. Antibiotics are recommended when there is surrounding cellulitis, extensive disease, facial involvement, diabetes or immunosuppression, multiple furuncles, or systemic signs. Empiric choices include agents active against Staphylococcus aureus, with adjustment for MRSA as needed (for example, doxycycline, TMP-SMX, or clindamycin; or a beta-lactam for MSSA such as cephalexin or dicloxacillin). Duration is typically 5–10 days. For recurrent disease, decolonization strategies (nasal mupirocin and chlorhexidine body washes) and hygiene measures may help reduce episodes.

Prognosis is generally good with proper drainage and treatment; recurrence is possible. Prevention focuses on hygiene, avoiding sharing personal items, and appropriate antibiotic stewardship. See also folliculitis, cellulitis, and carbuncle.