Definition of Sunburn:

A sunburn is reddening of the skin that occurs after you are exposed to the sun or other ultraviolet light.

See also: Sunburn first aid

Common Causes:

Sunburn results when the amount of exposure to the sun or other ultraviolet light source exceeds the ability of the body's protective pigment, melanin, to protect the skin. Sunburn in a very light-skinned person may occur in less than 15 minutes of midday sun exposure, while a dark-skinned person may tolerate the same exposure for hours.

It is now recognized that sunburn and sun exposure should not be treated as insignificant. Deaths have resulted from acute sun exposure, and significant temporary disability is experienced by millions of sunburned people each year.

Unlike a thermal burn, sunburn is not immediately apparent. By the time the skin starts to become painful and red, the damage has been done. The pain is worst between 6 and 48 hours after sun exposure. In severe sunburns, blistering of the skin may occur.

Swelling (edema) of the skin, especially in the legs, is common. Toxins are released with sunburn, and fever is not uncommon. Skin peeling usually begins between three and eight days after exposure.

The long-term consequences of years of overexposure to the sun are significant. One blistering sunburn doubles the likelihood of developing malignant melanoma. Chronic sun exposure causes premature wrinkling and aging of the skin. Age spots (lentigo) are a result of sun exposure.

Skin cancer (basal cell and squamous cell cancer) is directly related to the amount of sun exposure (determined by skin pigmentation and hours in the sun). Finally, sun exposure and ultraviolet damage have been implicated in the development of cataracts.

Very effective sunscreens have been developed that protect from UVA and UVB (long and short wavelengths of ultraviolet light), which are the components of sunlight responsible for burning and cancerous changes in the skin.

Sunscreen, protective clothing, and ultraviolet-protected sunglasses are all recommended to prevent excessive sun exposure. Wearing a sunscreen with high sun protection factor (SPF) is recommended. The higher SPF numbers indicate greater protection. Unfortunately, there is no way to get a "safe tan" from the sun.