sunburn

In medicine, skin damage caused by overexposure to sunlight.

Individuals with fair skin are particularly susceptible to the effects of sunlight due to the relative lack of melanin, a pigment that is made in certain cells in the skin. Skin reddening, due to dilation of blood vessels, occurs shortly after exposure to sunlight. This is followed by tanning as melanin production is stimulated. Overexposure to ultraviolet light, especially of medium wavelength (UVB), produces itching and tingling. Swelling of the superficial layer of the skin can be followed by blister formation and peeling. Headache and fever may also occur if sunburn is severe.

Exposure to the ultraviolet light produced by the sun results in thickening of the superficial layer of the skin and premature ageing. The longer wavelengths of ultraviolet light (UVA) are responsible for photosensitivity reactions and long-term damage to the skin. Prolonged exposure to the sun, especially in individuals with fair skin, is a risk factor in the development of skin cancers, including melanomas.