Sun allergy: what é, symptoms, causes and treatment

Sun allergy is an exaggerated reaction of the immune system to the sun's rays, which causes an inflammatory response in the regions most exposed to the sun, such as arms, hands, neck, chest and face, causing symptoms such as redness, itching and white or red dots. In more severe and rare cases, this reaction can even appear on the skin covered by clothing.

Although the cause of sun allergy is not yet known, it is possible that it happens because the body recognizes the changes caused by the sun in the skin as something "foreign", resulting in an inflammatory reaction.

This allergy can usually be prevented or alleviated through the use of sunscreen and appropriate treatment, which must be done under the guidance of a dermatologist and which may include the use of antihistamines.

Main symptoms

Sun allergy symptoms can vary from person to person, depending on the sensitivity of the immune system, however, the most common signs include:

• Red spots on the skin;
• Blisters or red spots on the skin;
• Itching in a region of the skin;
• Irritation and sensitivity in parts exposed to the sun;
• Skin burning sensation.

In some cases there may still be the formation of bubbles with transparent liquid inside, being more common in people with fair skin or who are undergoing treatment with medicines that cause sensitivity to sunlight.

These symptoms may appear within a few minutes after exposure to the sun, but depending on the sensitivity of each person, this period may be shorter. Also check out other causes that can cause red spots on the skin.

How to confirm the diagnosis

The diagnosis of sun allergy is made by a dermatologist through observation of symptoms, assessment of he alth history and tests of sensitivity to sunlight, such as phototests or epicutaneous testing, in which ultraviolet light at different lengths is used to check the skin reaction.

Another test that the doctor can perform is the patch test, which consists of applying substances to the skin and then UV radiation, to see if they cause sensitivity to the skin when in contact with radiation.

In addition, the doctor may also order other tests, such as blood tests or skin biopsy, mainly to rule out other conditions that may have similar symptoms, such as eczema or lupus, for example.

Possible causes

The exact cause of sun allergy is not fully known, however, some factors may contribute to its development, such as:

• Very fair and sensitive skin;
• Use chemical products on the skin, such as perfumes, repellents or even certain substances present in sunscreen;
• Use medications that cause sun sensitivity, such as tetracycline, sulfa, ketoprofen;
• Chemotherapy for the treatment of cancer;
• Other skin conditions such as dermatitis or psoriasis;

In addition, people with a family history of sun allergy also seem to be more likely to develop skin changes after sun exposure.

How the treatment is done

The treatment of sun allergy should be guided by the dermatologist and started with techniques to avoid prolonged contact with the sun, such as using sunscreen or wearing clothing that has sun protection and that covers most of the skin, for example.

In milder cases, the doctor may recommend the use of oral antihistamine medications, such as loratadine or fexofenadine hydrochloride, which help relieve itchy skin, or the use of creams or lotions containing calamine or aloe vera, to soothe the skin.

In addition, in more severe cases, the dermatologist may prescribe corticosteroid medications, such as prednisone, hydroxychloroquine or phototherapy treatment.

How to protect your skin from the sun

To protect the skin and prevent the onset or worsening of sun allergy symptoms, it is important to adopt some measures, such as:

• Avoid sun exposure, looking for shady places and spending as much time out of the sun as possible. See how to sunbathe without risks;
• Apply sunscreen on the skin with a minimum protection factor of 30, before leaving the house;
• Use a moisturizing lipstick with SPF 30 or higher;
• Avoid sun exposure in the hottest hours, between 10 am and 4 pm, as the sun's rays are more intense during this period;
• Wear sun protection clothes that have at least SPF 40, or prefer long-sleeved shirts and pants, for example. In summer, this type of clothing should be made of natural, light fabric and in light colors;
• Wear a cap or hat, as well as sunglasses, to protect your head and eyes from the sun's rays.

In addition, when allergy symptoms appear, it is recommended to apply cold water to the area and keep it protected from the sun, to reduce inflammation and relieve itching and redness, as well as apply a little gel of aloe to help soothe the skin.

However, in more severe cases, when intense itching and red plaques appear all over the body, one should still go to the hospital or consult a dermatologist.