Photodermatitis, sometimes referred to as sun poisoning or photoallergy, is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure. The second and subsequent exposures produce photoallergic skin conditions which are often eczematous. It is distinct from sunburn.
Signs and symptoms
Photodermatitis may result in swelling, difficulty breathing, a burning sensation, a red itchy rash sometimes resembling small blisters, and peeling of the skin. Nausea may also occur. There may also be blotches where the itching may persist for long periods of time. In these areas an unsightly orange to brown tint may form, usually near or on the face.
Causes
Many medications and conditions can cause sun sensitivity, including:
Sulfa used in some drugs, among them some antibiotics, diuretics, COX-2 inhibitors, and diabetes drugs.[1]
Prevention includes avoiding exposure to chemicals that can trigger the reaction, such as by wearing gloves, or avoiding sunlight or wearing sunscreen[3][4] preferably with at least factor 30 and with a high UVA protection level on the affected area. And by addressing any risk factors, such as those listed above.
^Rodriguez E, Valbuena MC, Rey M, Porras de Quintana L. 2006. Causal agents of photoallergic contact dermatitis diagnosed in the national institute of dermatology of Colombia. Photodermatol Photoimmunol Photomed 22(4): 189-192.
