Sunburn Health Article

Demographics

Infants and children are more likely to get sunburned than adults. Individuals who live in areas where the climate is mostly sunny year round (Arizona, southern California) are at higher risk both for sunburn and skin cancer. Those living at high altitudes are also at higher risk. The chance of being sunburned increases about 4 percent or every 1,000 feet (300 meters) rise in altitude. Fair-skinned, pale, freckled individuals are more likely to get sunburned than individuals with darker skin. Sunburn is extremely common. One poll found that in the summer of 1997, 13 percent of children had developed a sunburn in the preceding week.

Causes and symptoms

The ultraviolet rays in sunlight destroy cells in the outer layer of the skin, damaging tiny blood vessels underneath. When the skin is burned, the blood vessels dilate and leak fluid. Cells stop making certain proteins because their DNA is damaged by the ultraviolet rays. Repeated DNA damage can lead to cancer.

When UV rays burn the skin, immune system defenses that identify the burned skin as foreign are triggered. At the same time, the UV rays transform a substance on the skin that interferes with this immune response. While this keeps the immune system from attacking a person's own skin, it also means that any malignant (cancerous) cells in the skin will be able to grow freely.

Sunburn causes skin to turn red and blister. Symptoms appear from one to 24 hours after sun exposure and peak several days later, after which dead skin cells peel off. In severe cases, the burn may occur with sunstroke (vomiting, fever, and collapse). Severe cases of sunburn may require hospitalization.