A sun allergy is a condition that causes a rash after a person is exposed to sunlight. There are several types of sun allergies, and reactions can range from mild to severe. The most effective treatment strategy is to avoid the sun or cover your skin, but other treatments may help.
A sun allergy happens when a person develops a rash and sometimes other symptoms after exposure to sunlight. The allergy can range from mild to severe, possibly causing more serious symptoms or limiting everyday activities.
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There are different types of sun allergies, depending on the rash type, cause and people most often affected:
Sun allergies can affect anyone, including all ages, races and genders/sexes. Certain types are more common among people with lighter or darker skin. You also may be more likely to have a sun allergy if it runs in your family.
In addition, certain medications can increase your risk of having a photoallergic reaction. They include:
Sun reactions are more common in the spring and early summer, when people start to go out in the sun more often. With continued sun exposure over the summer months, skin can sometimes become resistant, lessening the likelihood of an allergic reaction.
Scientists don’t completely understand what causes sun allergies. Some studies have found genetic (inherited) patterns. Others have suggested that your body launches histamines or an immune response after sun exposure. There are probably several different causes, depending upon the type of skin reaction.
Sun allergy symptoms may appear a few minutes, hours or days after sun exposure. They can range from mild to severe, depending on:
The rash usually occurs only on areas that were exposed to sunlight. But sometimes, it can appear elsewhere on your skin.
A sun allergy rash may involve:
Rarely, sun allergy can cause systemic symptoms, such as:
The rash associated with sun allergy isn’t contagious.
If you suspect a sun allergy, talk to your primary care provider or a dermatologist.
They can diagnose the condition based on:
Rarely, your healthcare provider may order a skin biopsy to look at skin cells under a microscope.
The most effective treatment for sun allergy is avoiding sun exposure.
For people who cannot avoid the sun or who have more intense reactions, certain treatments may help:
Because scientists don’t fully understand what causes sun allergies, there aren’t any strategies to prevent the condition.
The prognosis for people with a sun allergy varies widely. Some people appear to outgrow the condition. But many can experience symptoms for 10 to 15 years or longer.
An episode of sun allergy often resolves a few hours to days after you get out of the sun. But the rash can last a couple of weeks. The rash generally doesn’t leave any scars unless you scratch and damage your skin’s surface.
If you have a sun allergy, use the following strategies to prevent episodes:
If you experience an episode:
If you have an allergic reaction to the sun, seek immediate medical attention if you develop any serious systemic symptoms:
A note from Cleveland Clinic
Sun allergy causes a skin rash and sometimes more serious symptoms. If you have a reaction to the sun, get indoors or under shade as soon as possible. Talk to your healthcare provider about ways to prevent future episodes.
Last reviewed by a Cleveland Clinic medical professional on 05/04/2022.
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