Sun Allergy

A sun allergy is not a true allergy. Far more commonly known as photosensitivity, in sensitive people prolonged exposure to UV radiation either from the natural sunlight or an artificial source such as a tanning booth can trigger an allergic-like reaction on the skin. This rash is commonly referred to as photodermatosis.

On the other hand, you can experience a photoallergic reaction. Generally, these are the result of a medication that has been applied to the skin. In such cases, UV light may structurally change the drug, causing the skin to produce antibodies. The result is an allergic reaction.

Symptoms can appear within 20 seconds after sun exposure, producing eczema-like skin conditions that can spread to nonexposed parts of the body. But sometimes, photoallergic reactions can be delayed. For example, Yuko Kurumaji reported in the October 1991 issue of Contact Dermatitis that photoallergic sensitivity disorders to the topically applied NSAID Suprofen (not approved for use in the United States) took up to three months to develop.

The degree of photosensitivity varies among individuals. Not everyone who uses medications containing photoreactive agents will have a photoreaction. In fact, a person who has a photoreaction after a single exposure to an agent may not react to the same agent after repeated exposures.

Photoreactive products can also aggravate existing skin problems like eczema, herpes, psoriasis and acne, and can inflame scar tissue. They can also precipitate or worsen autoimmune diseases, such as lupus erythematosus and rheumatoid arthritis, in which the body's immune system mistakenly destroys itself.

You can reduce your risk of a reaction to a sun allergy by:

Making sure your time in the sun is limited
Always wearing sunglasses and protective clothing when outside
Checking with your doctor before you use any topical treatments

Check with your doctor any time you have a skin reaction after being in the sun or a tanning booth. He should be able to work with you to determine the potential cause of the reaction and recommend a course of action to help prevent a reoccurrence. Using sunscreen may offer some protection. But sunscreens don't block out ultraviolet rays completely, and they won't help in the case of a photoreactive product.