If you have an itchy, red rash after being outside, you might be one of the 20 percent of people who are allergic to the sun.
Sun allergy, or polymorphic light eruption, is a condition in which the skin experiences adverse reactions after a person spends time outdoors. Rashes from sun allergy can take up to 10 days to go away.
The rash typically presents as an itchy, red rash, but a sun allergy can also cause hives, raised patches of skin, scaling, blisters, pain, and other symptoms as quickly as within a few minutes of sun exposure, according to the Mayo Clinic. Women, people with light-colored skin, and those with a family history of sun allergy have a higher risk of experiencing a rash from the sun, although the exact cause of the condition is unknown.
Sun exposure also is dangerous for people with eczema, as the heat can irritate the skin. Additionally, sweating leads to water loss from the skin, which can worsen the normal dryness and irritation associated with eczema. Chlorine can also aggravate eczema, resulting in itchy, red skin or hives. To minimize sun flare-ups of eczema it’s important to rinse off as quickly as possible after sun and chlorine exposure to remove the sweat and chlorine from the skin.
Cholinergic urticaria is a condition that causes cholinergic hives - pinpoint, raised, itchy red bumps with a white center that are triggered by heat, sweating, exercise and stress. These hives appear as your skin reacts to the heat and sweat as your body temperature goes up, but normally only last for 30 to 60 minutes. Allergists recommend using antihistamines and broad-spectrum sunscreens to control the hives.
Over-the-counter anti-itch cream with hydrocortisone or an oral antihistamine can help relieve some of the discomfort of sun rashes and hives. The best treatments for sun allergies and sensitivities is to prevent a reaction from occurring.
Limit the time you spend outdoors between 10 am and 2 pm, when the sun’s rays are the strongest. Don’t overdress during the summer, as this can increase sweating that will inflame your skin, but do cover skin as much as possible with loose cotton clothing.