This could be a sun-allergy, condition is called solar urticaria.Urticaria (or hives) is a skin condition, commonly caused by an allergic reaction, that is characterized by raised red skin wheals (welts). Wheals from urticaria can appear anywhere on the body, including the face, lips, tongue, throat, and ears. The wheals may vary in size from about 5 mm (0.2 inches) in diameter to the size of a dinner plate; they typically itch severely, sting, or burn, and often have a pale border.
Urticarias can be very difficult to treat. Drug treatment is typically in the form of Antihistamines such as diphenhydramine, hydroxyzine, cetirizine and other H1 receptor antagonists.
Counterirritants, such as mint oil, menthol, or camphor can be applied to the affected areas.Also Calamine lotion, containing zinc oxide and iron(III) oxide, is a traditional remedy for mild itching.