Paronychia

Acute or chronic inflammatory process of the periungual tissues of a finger or toe, characterized by painful erythema, swelling, and possible abscess or purulent collection adjacent to the nail plate and nail folds. Possible causes are bacterial (S. aureus, S. pyogenes), fungal (C. albicans), virus (HSV), moistrure/irritants (nail-biting/onychophagia, finger sucking, dishwashers, bartenders, housekeepers, cooks), diabetes, HIV, immunosuppression, and medications (retinoids, chemotherapy, antiretrovirals).