Sun allergy or Photoallergy

Sun allergies are an immunological response that occur when a photo allergen (a photosensitizing chemical) absorbs radiant energy and provokes an immune response. This allergy most often manifests as skin rashes and itching, although there are many different types of sun allergies, each with their own symptoms.

Description

Among the most frequent types of sun allergy are:

• Polymorphic light eruption (PLE): after sunburns, this type of allergy is the second most common skin disorder caused by the sun. Women are more affected than men, and symptoms usually first appear at a young age. Gradual and repeated exposure to the sun during spring and summer can decrease sensitivity to sunlight. While the effects of this desensitization process usually last throughout the warm season, symptoms will reappear the following spring.
• Hereditary polymorphic light eruption: usually characterized by more intense symptoms than the non-hereditary form, hereditary PLE often begins during childhood or adolescence.
• Photoallergic dermatitis: a form of sun allergy triggered by sunlight interacting with a chemical substance or a drug that has been taken or applied to the skin.
• Solar urticaria: causes hives on sun-exposed skin. While rare, it more often affects young women.

Causes of the bags under the eyes

The exact causes of sun allergies are not entirely known. What is understood is that the immune system recognizes some components of sun-altered skin as “foreign” and activates immune defenses against them. In some cases, the allergy is triggered by external factors, such as taking certain medications or using specific chemical products (creams, sunscreens, perfumes) that can make the skin more sensitive to the sun. Specific hereditary traits also appear to play a role.

Symptoms

The appearance of sun-allergic skin can vary depending on the underlying disorder. Symptoms can develop in a few minutes after exposure, but in some cases, signs may appear after several hours later. Symptoms can include:

• Redness
• Itching or pain
• Blisters or bubbles
• Hives similar to mosquito bites

Diagnosis

Doctors can often make a diagnosis of sun allergy through a dermatological examination. Other tests that may be used are: Photosensitivity test: a small area of skin is exposed to a controlled amount of ultraviolet light. If the typical symptoms of sun allergy appear after exposure, the test confirms a diagnosis of sun allergy.
Photopatch test: the skin is put in contact with the suspected allergy-triggering substance, and then exposed to ultraviolet radiation to test the reaction.
In rare cases, blood tests and a skin biopsy may be recommended to rule out systemic lupus erythematosus.

Treatments

Treatment depends on the particular type of sun allergy.
For mild cases, it may be sufficient to avoid exposure to the sun for a few days.
Phototherapy: with the arrival of the warm season, the doctor may suggest gradual exposure for several weeks to slowly reduce reactivity to ultraviolet rays.
In other cases, it may be necessary to use medications such as antihistamines or calcium antagonists.

Prevention

To prevent this type of allergy: Limit sun exposure and avoid the hottest hours of the day between 10am and 4pm; avoid sunbathing, or the sudden exposure to a lot of sunlight. In many people, symptoms appear precisely because sun exposure was unexpected, so by gradually increasing the amount of time spent outdoors the skin cells can adapt more easily; wear sunglasses and protective clothing when in the sun; avoid sun protection creams with chemical filters, as these often induce photosensitivity. Instead, to protect exposed parts of the skin from sunlight, use natural mineral light reflectors such as Sun Clay.