Hyperkeratosis in Skin Dimples in Children With Down Syndrome.

Down syndrome (DS) is a common chromosomal disorder with distinct phenotypes and skin markers. This study reports 39 DS patients, aged 1-44  months, who presented from birth with rough, brownish skin in the dimples of their knees and/or elbows. Dermoscopy revealed hyperkeratosis with brownish scales, and biopsies in six cases showed papillomatosis and mild hyperkeratosis. In the cases followed, the condition resolved spontaneously. Hyperkeratosis in the skin dimples on the knees and elbows seems to be a congenital and perhaps characteristic finding in patients with DS.