Picture of Photoallergic Reaction
Photoallergic reactions occur when exposure to ultraviolet (UV) light alters the structure of a drug and stimulates the immune system to react. Sun-exposed areas of the skin display inflammation, resembling eczema. These reactions take some time to resolve. Affected skin is red, itchy, and swollen. Substances that may provoke photoallergic reactions include certain pain medications, chemotherapy drugs, fragrances, antimicrobials, and sunscreens.
Text Reference: Skin Cancer Foundation: "Phototoxic Reactions versus Photoallergic Reactions"