A type of angiokeratoma that typically presents in childhood as a large, mostly linear and unilateral hyperkeratotic plaque which is composed of confluent keratotic papules. The size ranges from a few centimeters up to a major part of the body surface. Initially the lesions present asa multile reddish macules, clinically similar to a nevus flammeus. Within several years they develop into acanthokeratotic papules that agrregate into plaques which may have a hyperkeratotic surface. [from
HPO]