What is Actinic prurigo?

Actinic prurigo is a rare sunlight-induced, pruritic, papular or nodular skin eruption. Some medical experts use the term actinic prurigo to denote a rare photodermatosis that develops in childhood and is chronic and persistent; this rare photodermatosis, associated with the human leukocyte antigen HLA-DR4, is often called "Familial polymorphous light eruption of American Indians" or "Hereditary polymorphous light eruption of American Indians" but some experts consider it to be a variant of the syndrome known as polymorphous light eruption. Some experts use the term actinic prurigo for Hutchinson's summer prurigo and several other photodermatoses that might, or might not, be distinct clinical entities.