Diseases of the SKIN caused by or made worse by exposure to sunlight. In sufficient dosage, short-wave ultraviolet light (UVB – see ULTRAVIOLET RAYS (UVR)) always causes ERYTHEMA. Higher doses progressively cause OEDEMA and blistering; this is acute sunburn. Graduated exposure to UVB causes pigmentation (tanning). Prolonged chronic exposure to sunlight eventually accelerates ageing of the exposed skin with LENTIGO formation and loss of COLLAGEN and elastic tissue. After decades of such exposure, epidermal DYSPLASIA and CANCER may supervene.
Drugs given orally or topically may induce phototoxic reactions of various types. Thus, TETRACYCLINES exaggerate sunburn reactions. and the diuretic FRUSEMIDE may cause blistering reactions. Psoralens induce erythema and pigmentation. AMIODARONE also induces pigmentation. (See also PHOTOCHEMOTHERAPY.)
is a streaky, blistering rash typically seen on the limbs of children who have been playing in grassy meadows in summer. The phototoxic reaction is caused by psoralens in weeds.
is a pattern of streaky pigmentation usually seen on the neck, caused by a reaction to psoralens in perfumes.
Appropriate clothing and headgear, sunscreen creams and lotions are the main preventative measures.