Last week, we wrote about sunscreen allergies. Trying to juggle protecting yourself from the sun while avoiding allergy triggers seems hard enough; but can you imagine grappling with an allergy to the sun itself? What is a sun allergy?

Sun allergies are rare but real. Also called sun rash or solar urticaria, sun allergies are characterized by hives, itching, and redness that appear on skin that has been exposed to sunlight. Symptoms of a sun allergy often occur within minutes of sun exposure, and they usually recede less than a day after exposure has ceased.

Sun allergy is not merely a sensitivity to the sun, but a true allergy. Individuals with sun allergies produce antibodies against proteins found in their skin. When exposed to sunlight, the structure of these proteins changes, producing the antibodies reaction and the resultant hives. In extreme cases, an individual allergic to the sun can experience anaphylactic shock if exposed to too much sunlight.

Treatment of sun allergy includes antihistamines or the application of steroid creams. Oral steroids are also sometimes administered. Similar to the new peanut allergy treatment discussed recently, sun allergies may be treated by repeated exposure to sunlight. However, this should only be attempted under supervision by an allergist or dermatologist.