Characterized by diffuse hyperkeratosis of the
palms and soles, with a “honeycomb” appearance that progresses to
“starfish-shaped” keratotic plaques on the dorsa of the hands and feet,
and also involving the wrists, forearms, elbows, and knees. Fibrous
constricting bands (pseudoainhum) at the interphalangeal joints, which may
lead to autoamputation. May also be associated with hearing loss of varying
severity, cicatricial alopecia, ichthyosiform dermatosis, nail
abnormalities, mental retardation, and spastic paraplegia or myopathy.