You think you are allergic to the sun? Yes it's totally possible, and you are not alone! A sun allergy (also called sun poisoning, sun rash and photodermatitis) is a reaction of the immune system to sunlight, most often characterized as an itchy skin rash. A sun allergy is not sunburn but might feel like it. Sun allergies are believed to be induced by changes that occur to sun-exposed skin, but real causes are still unknown. Like other autoimmune conditions, the body activates its immune defenses against sun-altered skin. This produces an allergic reaction that takes the form of a skin rash or tiny blisters.
The 4 most common types of sun allergies are:
Polymorphous light eruption (PMLE)
PMLE is the most common sun allergy, affecting 10% of North Americans. Main symptoms include itchy or burning rash typically occurring within two to 24 hours after sun exposure. The rash usually appears on sun-exposed portions of the neck, upper chest, arms and lower legs, and may be accompanied by one to two hours of chills, headache and nausea.
Through repeated sun exposure, the person may become less sensitive to sunlight and the PMLE rash may disappear completely or gradually become less severe. Although the effects of this desensitization process, also called "hardening," usually lasts through the end of summer, the PMLE rash often returns at full intensity the following spring. A PMLE rash usually disappears within two to three days if further sun exposure is avoided. It could last more than fifteen days it skin is still sun exposed.
If you want to enjoy outdoor activities without discomfort, a lot of preventive treatment are available. You only have to test it and see what's working best for you.
Actinic prurigo (hereditary PMLE)
This inherited form of PMLE occurs in people of Native American background. Symptoms are usually more severe than classic PMLE and are concentrated on the face, especially around the lips. Several generations of the same family may suffer from this type of allergy.
This sun allergy is triggered by the effect of sunlight on a chemical that has been applied to the skin (more often an ingredient in sunscreen, fragrances and cosmetics) or ingested such as prescription medication. This usually causes an itchy red rash or tiny blisters. In some cases, eruption spreads to skin covered by clothing. Common prescription medication that can cause a photoallergic eruption include antibiotics, diuretics for high blood pressure and heart failure, and certain oral contraceptives. In most cases, skin symptoms disappear after the offending chemical is identified and no longer used.
This form of sun allergy is a rare condition. It produces hives (large, itchy, red bumps) on sun-exposed skin. Solar urticaria most often affects young women. Hives usually appear on uncovered skin within minutes of exposure to sunlight. Symptoms typically fade within 30 minutes to 2 hours. However, they usually come back when skin is exposed to sun again.
If you have mild symptoms of PMLE, you may be able to diagnose the problem yourself. Rash occurs only on sun-exposed skin during early spring (or a winter vacation in the Caribbean, for example) then gradually becomes less severe (or disappear) within the following few days or weeks. In most cases, your doctor can confirm that you have PMLE or actinic prurigo based on your symptoms, story and family history (in case of actinic prurigo).
If you have symptoms of a photoallergic eruption, your doctor will begin by reviewing your current medication as well as any skin lotions, sunscreens or colognes you use. The doctor may suggest that you temporarily switch to an alternate medication or eliminate certain skincare products.
Solar urticaria is a rare condition, your doctor may confirm the diagnosis by using photo-testing alone to reproduce your hives.
If you are prone to sun allergies, prevention (and reduced sun exposure) is the key to avoiding symptoms from worsening:
Be aware of any skincare products and medications that may trigger a photoallergic eruption. If you are taking prescription medication, and you normally spend a great deal of time outdoors, ask your doctor whether you should take any special precautions to avoid sun.
If you suffer from Polymorphous Light Eruption (PMLE) and still want to enjoy outdoor activities, learn more about the effect of alpha-glucosylrutin and vitamin E as a treatment for PMLE prone skin.