Common Causes of Hypopigmentation in Children.

Disorders of hypopigmentation are relatively common in children. Hypopigmentation refers to decreased pigmentation compared with surrounding skin, and depigmentation refers to a complete loss of pigmentation. The most common acquired causes include post-inflammatory hypopigmentation, pityriasis alba, vitiligo, tinea versicolor, and halo nevi. Commonly, congenital hypopigmented lesions may be attributed to pigmentary mosaicism, a term that refers to hypo- or hyperpigmentation resulting from somatic mosaicism. Pigmentary mosaicism most commonly occurs without syndromic association, such as in the case of nevus depigmentosus; however, rarely it can occur as part of a syndrome that may require further workup with genetic testing, such as with the hypomelanotic macules of tuberous sclerosis complex. Although most of the conditions causing hypopigmentation and depigmentation in children are benign, rare instances may be associated with syndromes or rare dermatoses that require further workup by a specialist. Given their common presentation to the general pediatrician, this article aims to cover the most common causes of hypo- and depigmentation in children, along with their differentiating features, natural history and prognosis, first-line treatment, and indications for further evaluation.