Intertrigo is a chronic inflammatory condition of approximating or opposing skin surfaces (intertriginous skin) such as the axillae, groin, abdominal folds, and/or labiocrural folds. Clinically, there is erythema and sometimes maceration, erosions, or fissuring. Intertrigo may be induced or exacerbated by any conditions causing increased heat, wetness, and friction. It may be worse during hot and/or humid weather. Incontinence is a predisposing factor in intertrigo of the perineum and crural folds, and there is significant overlap with diaper dermatitis. There is no ethnic or sex predilection. Intertrigo is seen more frequently at the extremes of age.

Intertrigo is often complicated by superficial skin infection with yeast or bacteria. In candidal intertrigo, the presence of outlying satellite papules and/or pustules is diagnostic.

Intertrigo is frequently complicated by secondary streptococcal infection in infants. This presents as bright erythema and maceration along the axillary, neck, and inguinal folds. Unlike candidal intertrigo, it lacks satellite pustules and is often more painful. The causative agent is group A beta-hemolytic streptococcus, and treatment involves topical antibiotics and oral penicillin.