Pityriasis alba revisited: perspectives on an enigmatic disorder of childhood.

Pityriasis alba (PA) is a localized hypopigmented disorder of childhood with many existing clinical variants. It is more often detected in individuals with a darker complexion but may occur in individuals of all skin types. Atopy, xerosis, and mineral deficiencies are potential risk factors. Sun exposure exacerbates the contrast between normal and lesional skin, making lesions more visible and patients more likely to seek medical attention. Poor cutaneous hydration appears to be a common theme for most risk factors and may help elucidate the pathogenesis of this disorder. The end result of this mechanism is inappropriate melanosis manifesting as hypopigmentation. It must be differentiated from other disorders of hypopigmentation, such as pityriasis versicolor alba, vitiligo, nevus depigmentosus, and nevus anemicus. Alleviation of the various risk factors via patient education on proper skin care and hygiene, use of lubricants and emollients, topical corticosteroid therapy in the presence of inflammation, and the novel administration of topical anti-inflammatory drugs such as calcineurin inhibitors can play a crucial role in promoting remission or resolution.