Sun allergy

Diagnosis

Your health care provider may diagnose sun allergy by looking at your skin. You might need tests, such as:

• Ultraviolet (UV) light testing. Also called phototesting, this exam is used to see how your skin reacts to light from a special lamp. This can help pinpoint which type of sun allergy you have.
• Photopatch testing. This test shows whether your sun allergy is caused by a sensitizing substance applied to your skin before you go into the sun. In the test, identical patches of common sun allergy triggers are applied to your skin, typically on the back. A day later, one of the areas receives a measured dose of UV rays from a sun lamp. If a reaction occurs only on the light-exposed area, it likely is linked to the substance being tested.
• Blood tests and skin samples. Your health care provider may have you undergo these tests if your symptoms might be caused by an underlying condition, such as lupus. With these tests, a blood sample or a skin sample (biopsy) is taken for examination in a laboratory.

Treatment

Treatment for sun allergy depends on the type you have and your symptoms. For mild symptoms, you may need to simply avoid the sun for a few days.

Medications

Creams containing corticosteroids are available in both nonprescription and prescription strengths. For a severe reaction, your health care provider may have you take prescription corticosteroid pills, such as prednisone, for a short time.

The malaria medication hydroxychloroquine (Plaquenil) may ease the symptoms of some types of sun allergies.

Phototherapy

If you have a severe sun allergy, your health care provider may suggest gradually getting your skin used to sunlight each year as the daylight hours get longer. In phototherapy, a special lamp is used to shine ultraviolet light on areas of the body that are often exposed to the sun. It's generally done a few times a week over several weeks.

Lifestyle and home remedies

These steps may help relieve sun allergy symptoms:

• Avoid sun exposure. Most sun allergy symptoms improve in less than a day or two if you keep the affected skin out of the sun.
• Stop using medications that make you sensitive to light. If you're taking medications for other conditions, talk with your health care provider about whether you can stop taking them if they are making your skin more sensitive to the sun.
• Apply moisturizers. Moisturizing skin lotions can help relieve irritation caused by dry, scaly skin.

Preparing for your appointment

You're likely to start by seeing your primary care provider. Or when you call to set up an appointment, you may be referred to a doctor who specializes in skin conditions (dermatologist).

At the time you make the appointment, be sure to ask if you need to do anything in advance. For example, if you're going to have tests that check for a reaction to ultraviolet light (phototesting), you might need to stop taking certain medications beforehand.

What you can do

Before your appointment, you may want to list answers to the following questions:

• How long after exposure to the sun did your symptoms begin?
• What type of symptoms did you experience?
• Have your symptoms worsened or gotten better?
• Have you ever had these types of symptoms before?
• What medications and supplements do you take regularly?

What to expect from your doctor

Your health care provider is likely to ask you a number of questions. Examples may include:

• What parts of your body are affected?
• Exactly what does the affected skin look like?
• How severe are your symptoms?
• How long does your skin reaction last?
• Do you have itching or pain?
• Does your skin react just to direct sunlight or also to sunlight shining through window glass?
• Does anyone else in your family have skin reactions to sunlight or other allergic skin conditions?
• What products do you use on your skin?