Heel-line hyperpigmentation: a variant of sock-line hyperpigmentation after the use of heel-length socks.

Two infants developed hyperpigmented curvilinear patches on the posterior heel after wearing heel-length socks. Both of the patient's lesions improved after discontinuing the use of the heel-length socks. Hyperpigmented patches called sock-line or mitten-line hyperpigmentation have been reported at sites of tight elastic bands from socks or mittens in infants on the calves and wrists. Recognizing this clinical entity is important to differentiate it from other causes of linear lesions such as child abuse or amniotic band syndrome.