What most people refer to as a sun allergy is actually photosensitivity or an abnormal sensitivity to sunlight. Skin that is photosensitive will develop and exaggerated response when exposed to sunlight. Sometimes the reaction occurs with very little sun exposure.
When a person has a sun allergy, the ultraviolet light (UV) is the causative factor creating the skin to be sensitive. There are instances in individuals having an adverse reaction to fluorescent lighting as well.
People with photosensitivity have an immunological response to UV light. Generally this manifests as some type of rash on the exposed skin. The immune system sees the changes in exposed skin as a foreign invader and responds to defend the body, causing an allergic reaction.
Some of the common types of photosensitivity (sun allergy) are:
- Polymorphous light eruption (PMLE)
After sunburn, PMLE is the most common skin problem associated with the sun. Occurring more often in spring and summer months when we spend more time outdoors, PLME is more prevalent in women, affects all races and typically begins in during early adulthood.
Usually produces an itchy or burning rash within 2 hours of sun exposure. The neck, arms, legs, and upper torso are most often affected. One to two hours of fever, headache, chills and general ill feeling can occur.
Treatment may include cool compresses, over the counter antihistamines, cortisone cream and limiting sun exposure or gradually building up the skin’s sun tolerance time.
- Actinic prurigo (hereditary PMLE)
A hereditary form of PLME occurring in American Indians, its symptoms are usually more intense than standard PLME. It also tends to appear earlier during childhood or adolescence.Symptoms are similar to PLME, but usually occur on the face. Treatments options include prescription strength corticosteroids, anti-malarial medications and beta-carotene.
- Photoallergic eruption
This is actually a skin reaction triggered by the combination of the sun and a chemical applied topically to the skin (usually sunscreen, fragrances or cosmetics) or medication ingested orally. Antibiotics (especially tetracyclines and sulfonamides) are common culprits causing the eruption. Certain other medications for high blood pressure and oral contraceptives have been known to create a reaction as well. There have also been cases of ibuprofen and naproxen sodium causing reactions.
Appears as itchy red rash or tiny blisters. Unexposed skin may also develop the rash. Because it is a delayed hypersensitivity to sun exposure, symptoms of photoallergic eruption may not appear until 1-2 days after being in the sun. Treatment begins with figuring out and eliminating the offending product or medication. Otherwise, relieving discomfort is achieved by over the counter cortisone cream and oral antihistamine.
- Solar urticaria
Within minutes of sun exposure this rare sun allergy produces hives of itchy red bumps on skin exposed to the sun.
You can also limit your risk of sun allergy by:
- Limiting sun exposure especially during peak hours (10 am -2 pm)
- Dress sensibly to limit exposure
- Avoid deliberate sun bathing
- Apply sunscreen regularly
Diagnosing sun allergy is generally done by history, visual examination and eliminating other more serious illnesses.