Sunlight contains ultraviolet A and ultraviolet B rays, both of which emit dangerous radiation. Exposure to sunlight and ultraviolet rays can damage the skin severely and lead to numerous complications, ranging from minor redness to life-threatening skin cancer. Some people are especially vulnerable to sunlight, and they can develop uncommon allergic-type reactions called sun poisoning.
Significance
A sun allergy occurs when areas of the skin exposed to sunlight react to the contact with the sun's rays by undergoing a change, such as blistering, itching or developing a rash. Sun poisoning typically refers to two types of sun allergies or reactions: polymorphous light eruption and solar urticaria. Both skin conditions are usually temporary and clear up spontaneously, although they may recur seasonally or after additional sun exposure.
Polymorphous Light Eruption Effects
Also called polymorphic light eruption or PMLE, polymorphous light eruption usually produces a red-colored rash after exposure to sunlight and other sources of ultraviolet radiation, such as tanning beds and tanning lamps. Although the rash can have various appearances, it often looks the same in specific individuals. Other symptoms include a burning sensation, blistering, itching, swelling and tiny bumps in the affected area. The rash generally goes away within several days.
Polymorphous Light Eruption Considerations
Polymorphous light eruption is twice as common in women than men and about half of sufferers have a family history of the condition, according to the American Osteopathic College of Dermatology. People with PMLE may develop rashes only rarely or each time their skin comes in contact with ultraviolet radiation. Rashes typically occur in the spring or at the beginning of summer and then become less frequent as the summer progresses and the skin becomes less sensitive to ultraviolet rays. The most common locations of PMLE rashes are the arms, lower legs, neck and upper chest.
Solar Urticaria Effects
Solar urticaria is much less common than PMLE. The rare skin condition produces hives—or large, red, swollen bumps—that often itch and sting. The reaction generally occurs quickly, within moments of contact with sunlight, and starts to go away within two hours. However, the reaction often recurs when skin is exposed to ultraviolet radiation again. As with PMLE, additional symptoms may include headache, nausea and general discomfort, especially when hives occur on large portions of the body.
Solar Urticaria Effects Considerations
Most common in adult females, solar urticaria typically appears for the first time around age 35, although it can affect people ranging from infants to the elderly. Scientists have not identified the exact cause of the condition, but research suggests the allergic reaction occurs when photoallergen, a chemical produced in the body, reacts with ultraviolet radiation. The resulting rash typically appears in areas that are usually covered, such as the back, while frequently exposed areas, such as the face, may not be affected at all or as much.
