Sunday, April 22, 2012

Sun Allergies: Symptoms and Treatment

A sun allergy is a reaction of the immune system, caused by sensitivity due to sunlight, and is known as photosensitivity. They occur when the sun-exposed skin reacts abnormally to sunlight. Scientist are still not able to understand the exact reason for its occurrence, though some research indicates inheritance as one of its reasons. The most common explanation is that the immune system treats the sun-altered skin as foreign substances and activates its defensive mechanism against it, causing allergic reactions.

Sun Allergies: Symptoms and Treatment
There are mainly four types of sun allergies. Sun allergy symptoms and treatments depend on the type of sun allergy. Following are the types, its symptoms and treatments.

Polymorphous Light Eruption (PMLE)
PMLE symptoms are an itchy or burning skin rash, as red plaques or small fluid-filled blisters, that can bleed on rupture, on the sun-exposed skin. It occurs within a couple of hours after sun-exposure and at times maybe accompanied by chills, headache or nausea. It usually occurs on exposed portions of the neck, upper chest, arms and lower legs. They tend to disappear on their own in a couple of days, but for some people it keeps re-occurring every spring and summer, resulting in a decrease in the skin's sensitivity to sunlight.

A mild reaction can be treated using a cold compress application or spaying the skin with cold water in frequent intervals. A more severe or hardened allergy is treated through medications such as an oral antihistamine, like diphenhydramine or chlorpheniramine, or any anti-rash skin cream containing cortisone. For extreme cases, doctors usually prescribe photo therapy treatment, where the skin is gradually exposed to ultraviolet light (UV), in small and frequent doses to build skin resistance to the sun. Sometimes, a combination of psoralen and ultraviolet light, antimalarial drugs or beta-carotene tablets are also used for treating PMLE sun allergy.

Actinic Prurigo
This form of sun allergy is an inherited form of PMLE. As its nature is inheritable, it begins early in life during childhood or adolescence. They share similar symptoms as PMLE form, but the rash occurs more on the face, than any other place. It re-occurs in spring and summer, while in tropical climates it persists round the year. Actinic prurigo sun allergy is treated using medications that include corticosteroids, thalidomide, antimalarial drugs, beta-carotene and UV, depending on the severity of the allergy.

Photoallergic Eruption
When the skin is exposed to sun, at times it reacts to the chemical component or substance present in the application used on the skin, such as sunscreen, fragrances, cosmetics or ointments and even to some prescribed drugs. The skin reacts and produces tiny red rashes or fluid-filled blisters. It may also spread through clothing, that covers the infected area. Most of the times, these symptoms present themselves after 2 to 3 days of sun exposure. The duration of photo allergic eruption, depends on the duration of the particular chemical substance used. The most common treatment prescribed by the doctor other than corticosteroid cream, is to find and eliminate the allergy causing products.

Solar Urticaria
This rare form of allergy is considered to be the only true form of sun allergy. It produces hives on the affected parts of the skin. It exhibits symptoms within minutes of exposure to sunlight, and if the hives are formed individually, they fade away within a couple of hours. It is treated as per its severity. For mild allergies, oral antihistamine or an anti-itch skin cream, containing cortisone is prescribed. For severe symptoms, a combination of psoralen and ultraviolet light, antimalarial drugs or beta-carotene tablets are used for its treatment.

Some over the counter medications like Vitamin E, Aloe Vera and quercitin (flavonoids) can prove to be helpful in treating and healing sun allergies. Besides these, preventive measures like using a good quality and high SPF sunscreen, and sun protection gear, should be used regularly. Exposure to sunlight cannot be avoided, but a few simple preventions taken, can save us the agony of dealing with sunburns and rashes