photosensitivity
(FOH-toh-SEN-sih-TIH-vih-tee)
A condition in which the skin becomes very sensitive to sunlight or other forms of ultraviolet light and may burn easily. Photosensitivity usually causes a rash or sunburn, especially on areas of the skin that are exposed to ultraviolet light. The affected areas may be painful and may itch, blister, or peel. Photosensitivity may be caused by certain medicines, such as antibiotics and anticancer drugs, radiation therapy, exposure to certain chemicals, and some medical conditions, such as lupus and xeroderma pigmentosum.