Hereditary sclerosing poikiloderma (HSP) is an extremely rare autosomal dominant disorder comprising generalized poikiloderma, sclerosis of palms and soles, linear and reticulated hyperkeratotic and sclerotic bands, and digital clubbing. HSP likely arises secondary to a de novo mutation, has variable penetrance, and is noted to be more severe in males. No mechanism leading to the characteristic clinical and histological changes has been identified. HSP has been observed in individuals of African, European, and Korean descent. Characteristic changes are absent at birth and appear early in childhood (usually between ages 2 and 4) with progressive poikiloderma. Sclerosis of the palms and soles appears later. One patient manifested subcutaneous calcification. Cardiac valvular abnormalities, including calcific changes, have been reported in some cases.