Sun allergy – types, causes, symptoms, treatment

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People regularly have allergies to pollen, pet dander, peanuts, latex, and crustaceans, but the one that seems unlikely is an allergy to sunlight. Scientists are just beginning to understand how widespread sun allergy really is. Read about sun allergy, what types of sun allergies are and how to treat them.

Sun allergy – what is it?

Sun allergy is a reaction of the immune system to sunlight, with an itchy red rash the most common. The most common locations are the neck area, the back of the hand, the outer surface of the arms and lower legs. In rare cases, the skin reaction may be more severe, causing hives or small blisters which may even spread to the skin under clothing.

Sun allergies are caused by changes in your skin when it is exposed to the sun. It is not clear why the body develops this reaction. However, the immune system recognizes some of the components of the sun’s changed skin as ‘foreign’ and the body activates its immune defenses against them. This causes an allergic reaction which may take the form of a rash, tiny blisters or, rarely, some other type of skin eruption.

Sun allergy – types

Allergy to the sun only occurs in some sensitive individuals, and in some cases can only be triggered by a few brief moments of sun exposure. Some forms of sun allergy are hereditary.

A few of the most common types of sun allergy are:

1. sun pruritus (hereditary PMLE) – this hereditary form of PMLE is found in people of American Indian descent, including the North, South and Central American Indian populations. The symptoms of itching are usually more severe than with classic PMLE and often begin earlier in childhood or adolescence. Several generations of the same family may struggle with sunburn,
2. photoallergic eruption – In this form of sun allergy, a skin reaction is caused by exposure to sunlight on a chemical that has been applied to the skin (often an ingredient in sunscreen, perfumes, cosmetics, or antibiotic ointments) or after ingesting a drug (often a prescription drug). Common prescription medications that can cause photoallergic eruption include antibiotics (especially tetracyclines, fluoroquinolones and sulfonamides), NSAID pain relievers, ibuprofen and sodium naproxen, and diuretics, medications for high blood pressure and normal heart function.
3. solar urticaria – This form of sun allergy causes hives (large, itchy, red bumps) on skin exposed to the sun. Young women are most often affected by this form of sun allergy.

See also: Solarium – benefits, disadvantages, contraindications

Allergy to the sun – drugs and medical preparations

Here is a list of some medications and medications that may affect the appearance of sun allergy.

Anti-anxiety drugs:

1. Alprazolam,
2. Chlordiazepoksyd,

Antibiotics:

1. Quinolone,
2. Sulfonamidy,
3. Tetracyclines (especially doxycycline),
4. trimethoprim,

Antidepressants:

1. Tricyclic antidepressants,

Antifungal drugs:

1. Griseofulvin,

Antihyperglycemic drugs:

1. Sulfonylureas,

Antimalarial drugs:

1. Chlorochina,
2. Quinine,

Antipsychotics:

1. Phenothiazines,

Chemotherapy drugs:

1. Dakarbazyna,
2. Fluorouracyl,
3. methotrexate,
4. winblastyna,

Diuretics:

1. furosemide,
2. Thiazides,

Drugs for the treatment of acne:

1. isotretinoin,

Cardiac drugs:

1. Amiodarone,
2. Chinidyna,

Painkillers:

1. Non-steroidal anti-inflammatory drugs (NSAIDs; especially piroxicam and ketoprofen).

See: Aspirin and NSAIDs fight cancer

Sun allergy – who is exposed?

Sun allergy is a common condition that affects up to 10 percent of the population. Women and fair-skinned people are more prone to PMLEwhich is most common in regions with different seasons, such as the northern climate. Countries near the equator have much lower PMLE cases because people there are exposed to higher levels of UV radiation all year round.

Continuous exposure to intense sunlight allows them to build up a tolerance to UV radiation, which protects against sun allergy. In areas with low UV radiation in winter, people with PMLE tend to have more severe symptoms in the spring. Their symptoms subside in the summer months as they become more tolerant to UV radiation.

The editorial board recommends: The ingredients of grapes protect the skin against UV rays

Sun allergy – symptoms

Symptoms vary depending on the specific type of sun allergy:

1. photodermatosis (PMLE) – PMLE usually causes an itchy or burning rash within the first two hours of sun exposure. The rash usually appears on sun-exposed parts of the neck, upper chest, arms, and lower legs. In addition, one to two hours of chills, headache and malaise (general nausea) may occur. In rare cases, PMLE may appear as red blisters (flat, raised areas), small fluid-filled areas, or tiny areas of bleeding under the skin.
2. sun pruritus (hereditary PMLE) – the symptoms are similar to those of PMLE, but are usually concentrated in the face, especially around the mouth,
3. photoallergic eruption – usually causes itchy red rash or small blisters. In some cases, the skin eruption also spreads to the skin covered with clothing. Since photoallergic eruption is a form of delayed hypersensitivity reaction, skin symptoms may not appear until one to two days after sun exposure.  
4. solar urticaria – hives usually appear on exposed skin within minutes of exposure to sunlight.

Read: The woman is allergic to… exercise

Sun allergy – course

The duration of the reaction depends on the type of sun allergy:

1. PMLE – PMLE rash usually disappears within two to three days if you avoid further sun exposure. In spring and summer, repeated exposure to the sun can cause hardening, which is a natural decrease in skin sensitivity to sunlight. Some people develop sclerosis after just a few days of sun exposure, while others it lasts for several weeks.
2. sun pruritus (hereditary PMLE) – in temperate climates, sun pruritus has a seasonal pattern similar to classic PMLE. However, in tropical climates, symptoms can persist throughout the year,
3. photoallergic eruption – the duration is unpredictable. However, in most cases, the skin symptoms disappear after the harmful chemical is identified and stopped using it.
4. solar urticaria – individual blisters, blemishes usually disappear within 30 minutes to two hours. However, they usually come back when the skin is exposed to the sun again.  

See: Anaphylaxis – a minor allergy or a deadly threat?

Sun allergy – prophylaxis

To avoid allergy to the sun, protect your skin from exposure to sunlight. Follow these rules to avoid sun allergy:

1. before going outside, apply a sunscreen that has a sun protection factor (SPF) of at least 30 or more, with a broad spectrum of protection against both ultraviolet A and ultraviolet B rays – try Shaka Stick Sunscreen, for example Sun, 
2. use sunscreen on your lips. Choose a product that has been specially developed for the lips, with an SPF 30 or higher,
3. tame your time outdoors when the sun is at its peak, especially in summer – from around 10 a.m. to 15 p.m.  
4. wear sunglasses with protection against ultraviolet radiation,
5. Be aware of skin care products and medications, especially some antibiotics that can trigger a photoallergic eruption. If you are taking prescription medications and usually spend a lot of time outdoors, ask your doctor if you should take any special precautions to avoid sun exposure while taking the medication. 

It is worth remembering that even without direct contact with the sun, you can achieve a beautiful tan effect. You can use Bioherba Peach Self-Tanning Body Lotion or Bioherba Moisturizing Bronzing Cream.

The editorial board recommends: Which sunglasses to choose? Important advice from an ophthalmologist

Sun allergy – treatment

If you are allergic to the sun, treatment should always begin with the strategies outlined in the Prevention section. They will reduce your exposure to the sun and prevent your symptoms from getting worse. Other treatments depend on your specific type of sun allergy:

1. PMLE – for mild symptoms, apply cool compresses to the areas of the itchy rash or spray the skin with streams of cold water. You can also try an oral antihistamine such as diphenhydramine or chlorpheniramine (both sold under several brands) – to relieve itching or a cream containing cortisone. For more severe symptoms, your doctor may suggest a prescription antihistamine or corticosteroid cream. If these measures are not effective, your doctor may prescribe phototherapy, a procedure that causes hardening by gradually exposing your skin to increasing doses of ultraviolet light in a doctor’s office.
2. sun pruritus (hereditary PMLE) – treatment options include prescription corticosteroids, thalidomide, antimalarials, and beta-carotene.
3. photoallergic eruption – The first goal of treatment is to identify and eliminate the drug or skin care product that is causing the allergic reaction. Skin symptoms can usually be treated with corticosteroid cream.
4. solar urticaria – for mild urticaria, you can try an over-the-counter oral antihistamine to relieve itching, or a cortisone anti-itching cream. For more severe hives, your doctor may recommend a prescription antihistamine or corticosteroid cream. In extreme cases, the doctor may prescribe phototherapy.

Sun allergy – when to see a doctor?

Call your primary care physician or dermatologist if you have:

1. itchy rash that doesn’t respond to over-the-counter medications
2. rash that affects large areas of the body including parts covered with clothing
3. abnormal bleeding under the skin in sun-exposed areas.

Get emergency help right away if you suddenly develop hives together with swelling around your eyes or mouth, fainting, or have difficulty breathing or swallowing. These could be symptoms of a life-threatening allergic reaction.