Understanding Sun Allergy: Causes, Symptoms, and Treatments

You can be allergic to the sun. A sun allergy—sometimes also called photosensitivity—occurs when the skin is hypersensitive to ultraviolet (UV) rays, which the sun naturally emits. Signs of sun allergy can include an itchy, painful, blistering, or peeling rash. This reaction can occur within minutes or hours of sun exposure and can vary in intensity from mild discomfort to severe skin irritation.

Genetics, certain medications, and underlying autoimmune conditions can cause sun allergies. Treatments for sun allergies range from lifestyle modifications to medications, depending on the severity and type of sun allergy. Researchers aren’t sure how many people sun allergies affect, but an estimated 2% to 18% of people worldwide may live with a sun allergy.

There are different types of sun allergies, each with its different causes, triggers, and symptoms. The four main types of sun allergy include:

Sun allergy symptoms can vary from person to person, depending on the severity and type of sun allergy they have. While some people may have only mild symptoms, others may develop more severe reactions to sunlight exposure. 

PMLE symptoms usually develop within hours to four days after sun exposure, and you may experience:

Symptoms of solar urticaria often develop within minutes of sun exposure and may include:

Medications and certain cosmetic products may cause a photoallergic reaction to the sun. As a result, you might experience the following symptoms within hours or days of sunlight exposure:

With actinic prurigo, symptoms usually appear shortly after sun exposure and resolve within a few days. Additional sun exposure can re-trigger the allergic reaction to sunlight and cause a recurrence of symptoms, including:

Sun allergies occur when the skin has a hypersensitive reaction to sunlight or artificial ultraviolet (UV) rays such as tanning beds. When you have a sun allergy and spend time in sunlight, your immune system perceives UV rays as a threat.

As a result, the immune system produces and releases inflammatory chemicals (e.g., histamines) to protect the body. The release of histamines and other immune system cells leads to skin inflammation, rash, and other sun allergy symptoms.

The following causes and risk factors can increase your likelihood of developing sun allergy symptoms:

To diagnose a sun allergy, a healthcare provider will thoroughly review your personal and family medical history, ask about your symptoms (such as when they developed and how long they lasted), and perform a physical examination.

The provider will generally try to rule out other possible causes of your symptoms. They may evaluate your symptoms using one or more of the following tests:

While there is no cure for most sun allergies, treatments can help relieve symptoms, reduce the frequency of allergic reactions, and improve your quality of life. Treatment options vary based on the specific type of sun allergy and the severity of symptoms. A provider can recommend a combination of lifestyle changes, medications, and therapies.

Making adjustments to your lifestyle may help manage a sun allergy. This may include:

For mild sun allergies, a provider may recommend over-the-counter hydrocortisone creams or ointments that you can apply directly to the skin. These topical medications can help relieve itching and inflammation after an allergic reaction. In some cases, the provider may opt to prescribe stronger corticosteroid creams for more severe reactions.

A healthcare provider may prescribe oral medications (taken by mouth) for severe sun allergies to help you manage symptoms and prevent future allergic reactions. These medications may include:

Light therapy involves controlled, gradual exposure to UV light that may help desensitize skin to sun exposure and reduce reactions to sunlight. Phototherapy is a common treatment approach for PMLE.

While there is no surefire way to prevent most sun allergies, there are several things you can do to help reduce the frequency and severity of allergic reactions to sunlight, such as:

Certain conditions may increase your risk of developing a sun allergy. These include: 

Living with a sun allergy can profoundly affect your life, from everything between work to leisure activities with friends and family. While living with a sun allergy can be challenging, embracing lifestyle adjustments and taking your medications (if any) as prescribed can help you manage your symptoms, spend time outdoors, and lead a fulfilling life.