“Allergy to the sun” is the colloquial name of a series of diseases that generate reactions and skin problems related to exposure to sunlight. Actually, the term is wrong, as most of these reactions are not allergic.
These are the risks of not exposing yourself to the sun at all
An allergy is a reaction to extreme sensitivity by the immune system against a substance that it considers harmful or harmful, but that does not cause any discomfort to most people. On the other hand, in almost all the cases that are usually called “sun allergy”, the immune system is not involved.
Therefore, a more appropriate way to call these problems – rather than sun allergy – is photodermatosis or photosensitivity diseases. This is explained by the allergist María Dolores del Pozo Gil in a Article which is part of the Allergic Diseases Book, edited by the BBVA Foundation.
Symptoms on the skin of possible “allergies”
When dealing with various pathologies, sun allergy symptoms They also differ, although the most common – according to the experts of the Mayo Clinic, from the United States – are the following:
- redness of the skin
- itching or pain
- sometimes small lumps
Beyond this variety in symptomatology (and also in its frequency, severity and evolution), Del Pozo Gil points out that the existence of a photodermatosis should be suspected whenever there is a skin rash in the most exposed areas in sunlight, such as the face, neck, or back of the hands.
The most common photosensitivity diseases
1. Polymorphous solar eruption
Considered the most common of the photodermatoses, it can affect up to 15-20% of the general population. It causes “a skin rash of varied morphology,” says Del Pozo Gil, “which is predominantly located on the face, décolleté, forearms and anterior area of the legs.”
It mainly affects young women. As it usually appears with the first exposures to intense sunlight, it is more frequent in spring and early summer. And you don’t have to lie down to sunbathe to suffer it: a walk may be enough.
2. Solar urticaria
Solar urticaria is often confused with polymorphous solar eruption, since it often presents similar symptoms. However, the lesions are usually larger (such as hives or hives), affects men and women equally and not only in areas of the skin exposed to the sun, but in any part of the body.
It happens that the one produced by solar urticaria is an allergic reaction. “It is produced by a mechanism of immediate hypersensitivity in front of an unknown photoallergen, “says Del Pozo Gil.
It is much less common than polymorphous solar flare. But when it affects a very large surface the reaction can include other problems, such as headache, nausea, shortness of breath and drops in blood pressure.
3. Phototoxic reactions
Phototoxic reactions require, to occur, the sum of two factors. On the one hand, contact with sunlight. On the other, the intake of a drug, usually orally.
It can happen with so common drugs such as anti-inflammatories (including ibuprofen), antibiotics, contraceptives, antihypertensives, and common psychotropic drugs (such as diazepam).
These reactions can appear in a matter of few hours and even minutes, in the form of a rash, blisters, or severe burns. They can appear in people of any gender and age, so it is advisable to pay close attention to the suspicion of their emergence.
4. Photoallergic reactions
The so-called photoallergy also shows its reactions when exposure to sunlight is combined with a substance external to the body, but in this case those substances are in general creams or cosmetics. They take a little longer to appear (between twelve hours and three days) and cause swelling and itching, similar to the contact dermatitis.
The substances that most frequently generate these reactions vary over time. A few decades ago, the most common were soaps and perfumes that included these photoallergens in their composition. At present they tend to occur mostly with sunscreen creams or anti-inflammatory ointments.
5. Actinic prurigo
Actinic prurigo consists of an exaggerated reaction of the skin to solar radiation. It is a chronic disease, more common in older people or of Latin American origin, and mainly affects women. It is itchy, and intense scratching usually leads to a thickening of the skin.
6. Cutaneous porphyrias
There are several types of cutaneous porphyrias. In general, they are caused by a deficiency (or sometimes an excess) of certain enzymes, which cause the body to overproduce a substance known as phototoxic porphyrins. The result is a negative reaction to sunlight. In addition to rashes, redness, and blisters, these porphyrias can cause abdominal pain and seizures.
Measures to prevent “allergies”
Many of these problems can be treated with medication, especially with antihistamines and corticosteroids. Therefore, it is advisable to go to the doctor as soon as reactions like these are detected.
In most cases, such reactions they do not leave scars nor other permanent effects. From the discovery of any of these pathologies, specialists highlight the importance of assuming certain behaviors to avoid their negative effects, or at least reduce the chances of their occurrence.
A general preventive measure consists of avoid incidence direct of the sun’s rays in the central hours of the day: between 12 and 17. It is also essential – and not only to avoid these “allergies” but also to avoid long-term skin damage – the use of creams with a high protection factor (at least 30).
Clothing used on sunny days is also key: long-sleeved garments, hats or caps, and sunglasses should be prioritized to mitigate the impact of UV rays on the body.
Another measure that can avoid or reduce certain negative effects is, at the beginning of the summer season, getting out in the sun gradually and not sudden. If you start with short periods of time, the body has time to adjust and the chances of problems will be less.
For the rest, there are more serious pathologies, considered photoexacerbated dermatoses. These include some well-known diseases, such as psoriasis, rosacea, and lupus. In these cases, extreme care must be taken, heed the doctor’s advice and eventually find ways to counteract the risks and damages of not being exposed to the sun.
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