allergens in a fashion similar to adults The distribution, shape, pattern of the rash, and exposure history, may elucidate the cause ( Table 65.3 ) Some common contactants include blue dye in diapers and preservatives in wet wipes, which trigger an itchy diaper rash; toilet seat cleaning supplies triggering “toilet seat dermatitis ” on the posterior thighs; and the vinyl lining of certain car seats which can cause “car seat dermatitis ” on the outer elbows, posterior calves, and occipital scalp Airborne processes (e.g., perfumes, body spray, spray deodorant) can trigger a rash on exposed surfaces, including eyelids, upper chest, distal arms, and legs Photoallergic contact dermatitis occurs when an allergen is applied to the skin and exposed to the sun Common agents implicated include phenothiazines, sulfonamides, thiazides, sunscreen components such as PABA, and some fragrances