Diaper dermatitis generally refers to the irritant contact dermatitis that may result from multiple factors in the area: macerated skin (softened by being wet), rubbing and wiping, and possibly the presence of ammonia in urine and proteases and lipases in stool—all of which cause skin irritation and breakdown. It can become complicated by secondary bacterial or yeast infections as well.
The so-called “Greek method” of washing the soiled diaper area under a running tap of warm water rather than using abrasive wipes is said to prevent diaper dermatitis.
SYNONYMS Diaper rash, nappy rash.
AGE Most babies develop some form of diaper dermatitis during their diaper-wearing years. The peak incidence is between ages 9 and 12 months.
PREVALENCE At any one point in time, up to one-third of infants may have diaper dermatitis. The prevalence of severe diaper dermatitis (defined as erythema with ulcerations, oozing papules, and pustules) is 5%.
ETIOLOGY Excessive hydration of the skin and frictional injury lead to a compromised skin barrier, compounded by irritation from ammonia, feces, cleansing products, fragrances, and possible superinfection with Candida albicans or bacteria.
SEASON Reportedly highest during winter months, perhaps due to less frequent diaper changing.
The warm moist environment inside the diaper and frictional damage decrease the protective barrier function of the skin in the diaper area. Additional predisposing factors such as seborrhea, atopic dermatitis, and systemic disease— as well as activating factors such as allergens (in detergents, rubbers, and plastic), primary irritants (ammonia from urine and feces), and infection (by yeast or bacteria)—lead to a rash in the diaper area. Diarrheal illnesses may acutely worsen diaper dermatitis given the frequent wet diapers with fecal material and propensity for maceration.
TYPE OF LESION Ranges from macular erythema (Fig. 3-1) to papules, plaques, vesicles, erosions, and rarely ulcerated nodules.
Red, macerated areas in the diaper region of an infant.
COLOR Ranges from mild erythema to diffuse beefy redness.
PALPATION Ranges from nonindurated to prominently elevated lesions.
DISTRIBUTION Diaper area, convex surfaces involved, folds spared. Severe cases may involve folds and have characteristic C. albicans satellite pustules if superinfected.
DIAGNOSIS The diagnosis of diaper dermatitis may be made clinically, although refractory response to conventional treatments should raise the suspicion of less common rashes in the diaper area.
DIFFERENTIAL DIAGNOSIS Diaper dermatitis must be differentiated from psoriasis, granuloma gluteale infantum (likely a foreign body reaction, typically to baby powder, ...