Ichthyosis and psoriasis in a patient with Down syndrome.

A 24-year-old man with Down syndrome presented with prominent ichthyosiform skin on his extremities and psoriatic plaques on his chest, back and scalp. The late onset of his ichthyosis without family history suggested that it was not a heritable form but was associated Down syndrome. Such an association with ichthyosis and psoriasis has not been described previously.