Irritant diaper dermatitis (IDD, also called a diaper or nappy rash) is a generic term applied to skin rash in the diaper (in British and Australian English "nappy") area that are caused by various skin disorders and/or irritants. Generic irritant diaper dermatitis is characterized by joined patches of erythema and scaling mainly seen on the convex surfaces, with the skin folds spared. Diaper dermatitis with secondary bacterial or fungal involvement tends to spread to concave surfaces (i.e. skin folds), as well as convex surfaces, and often exhibits a central red, beefy erythema with satellite pustules around the border. It is usually considered a form of irritant contact dermatitis...