What is a sun allergy?
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.
What are the different kinds of sun allergies?
There are different types of sun allergies, depending on the rash type, cause and people most often affected:
- Actinic prurigo: Actinic prurigo causes raised papules or nodules on your skin. The rash can affect additional areas of skin that haven’t been exposed to the sun. It’s more common among Latin American and American Indian populations with darker skin. Actinic prurigo appears to have a genetic link. It’s also called hydroa aestivale and Hutchinson’s summer prurigo.
- Photoallergic reaction: This type of sun allergy occurs when a chemical applied to your skin reacts with sunlight. Examples include medications, sunscreens, makeup and fragrances. Symptoms may show up a few hours or days after sun exposure.
- Polymorphous light eruption: Polymorphous light eruption (PMLE) is more common in women and people assigned female at birth (AFAB), people with lighter skin, teenagers and young adults. It often appears as small bumps, patches or blisters a few hours after your skin has been exposed to sun.
- Solar urticaria: This type of sun allergy causes hives after just a few minutes of sun exposure. Symptoms can be mild to severe.
Who might get a sun allergy?
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:
- Cholesterol-lowering drugs.
- Hormones such as the birth control pill.
- Nonsteroidal anti-inflammatory drugs.
- Retinoids, often used for acne and anti-aging.
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.
Symptoms and Causes
What causes it?
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.
What are the symptoms of a sun allergy?
Sun allergy symptoms may appear a few minutes, hours or days after sun exposure. They can range from mild to severe, depending on:
- Amount of skin surface exposed.
- Amount of time in the sun.
- Intensity of light.
- Type of sun allergy.
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:
- Bumps, papules, nodules, blisters or hives.
- Scaling or crusting.
- Stinging or burning sensation.
Rarely, sun allergy can cause systemic symptoms, such as:
- Light-headedness or fainting.
- Nausea and vomiting.
- Wheezing or shortness of breath.
- Life-threatening anaphylaxis (with solar urticaria).
Is sun allergy contagious?
The rash associated with sun allergy isn’t contagious.
Diagnosis and Tests
How do you know if you’re allergic to the sun?
If you suspect a sun allergy, talk to your primary care provider or a dermatologist.
They can diagnose the condition based on:
- Discussion of your symptoms.
- Review of medications you take and products you put on your skin.
- Light testing, which involves placing different light sources (artificial and natural), wavelengths and intensities a few centimeters from your skin. It helps you understand what exactly causes a reaction. Light testing can be combined with patch testing. Your healthcare provider places patches on your skin that contain chemicals suspected to cause a reaction.
Rarely, your healthcare provider may order a skin biopsy to look at skin cells under a microscope.
Management and Treatment
What are some sun allergy treatment options?
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:
How can I reduce my risk of an allergic reaction to the sun?
Because scientists don’t fully understand what causes sun allergies, there aren’t any strategies to prevent the condition.
Outlook / Prognosis
What can I expect if I have a sun allergy?
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.
How do I take care of myself if I have a sun allergy?
If you have a sun allergy, use the following strategies to prevent episodes:
- At the start of spring and summer, gradually increase the amount of time you spend in the sun. This’ll help your skin adapt.
- Avoid the sun when it’s strongest, from 10 am to 4 pm. Stay indoors or in the shade.
- Stop using any medications and products that cause photosensitivity.
- Use protective items, including wide-brimmed hats, long sleeves, pants and window films to block the sun’s rays.
- Wear sunscreen with at least 30 SPF. Reapply every two hours or more often if you’re sweating or swimming.
How do you calm a sun allergy?
If you experience an episode:
- Get out of the sun.
- Place cool, damp clothes on the affected areas of your skin.
- Stay hydrated by drinking plenty of water.
- Take an antihistamine, which is available over the counter.
When should I see my healthcare provider?
If you have an allergic reaction to the sun, seek immediate medical attention if you develop any serious systemic symptoms:
- Chest pain.
- Muscle cramps.
- Severe headache.
- Stomach pain.
- Sudden and severe weakness.
- Trouble breathing or swallowing.
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.
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