Lesions typically appear hours or days after exposure of the skin to UV light, and follow a general pattern of sun-exposed areas.
The face, neck, arms, hands, and legs are often affected, although lesions sometimes appear on skin that is covered by clothing and thus not exposed to UV light, thus making AP somewhat difficult to diagnose.
AP is a chronic disease, and symptoms usually worsen in the spring and summer as the day lengthens and exposure to sunlight increases.
The cause for actinic prurigo is unknown, however researchers believe that protein in our bodies may be a cause to the condition also: •UV-A and UV-B light seem to be the main provoking agents.
However, some patients who are affected already live at sea level.18,19,27 •Some authors are considering a food photosensitizer or a nutritional selective deficiency as a cause; however, no evidence proves this theory.27 Currently there is no cure for actinic prurigo, and treatment focuses on relieving the dermatologic symptoms, by way of topical steroid creams or systemic immunosuppressants.