Sun allergy: symptoms and treatment
A sun allergy usually occurs after direct exposure to the sun. The exact causes have not yet been clarified. In this article you will find out exactly how a sun allergy manifests itself, how it is diagnosed and what you can do about it.
What is sun allergy?
Various intolerance reactions of the skin to sunlight are referred to as sun allergies. The colloquial name sun allergy is therefore basically misleading, since in most cases it is not a real allergy, but the symptoms only resemble those of allergic reactions.
The most common form of sun allergy, which occurs in about 90 percent of people with sun allergies and is described in this article, is medically referred to as polymorphic light eruption (PLD). In Germany, about 20 percent of the population is affected. In principle, sun allergies can occur in anyone, regardless of skin type. Statistically, however, sun allergies primarily occur in children and young women.
What causes a sun allergy?
The causes of the occurrence of a sun allergy have not yet been clearly clarified. One theory assumes that the UV rays in sunlight, especially UV-A, react with an endogenous substance and form an allergen. The immune system is then told to fight off the allergen, causing an allergic reaction. Another theory is that exposure to the sun leads to the release of free radicals in the skin, which also trigger an immune system response.
It is also often assumed that a sun allergy is triggered by the interaction of sunlight and chemical substances in detergents, creams, perfumes or medicines. This is also how the so-called “Mallorca acne” develops, for which a reaction of sunlight with fatty sunscreens is held responsible.
How does a sun allergy manifest itself?
As the medical name suggests, a sun allergy can manifest itself in very different ways and with variable characteristics, because polymorph means something like “many forms”. However, one or more of the following symptoms are usually present:
- skin redness
- Burning and intense itching
- Lumps and blisters on the skin
The symptoms usually appear with a time lag, i.e. hours or a few days after exposure to the sun. Usually only the parts of the body that were directly exposed to sunlight are affected, which is often the face, neck, décolleté, upper arms, thighs and backs of the hands.
The symptoms usually subside on their own after a few days, provided the patient avoids sunlight during this time. Normally, there is no permanent damage to the skin.
How is sun allergy diagnosed?
In order to diagnose a sun allergy, the attending doctor will first ask about the individual medical history. He will want to know when and where the symptoms occur, what their extent is and whether any other allergies are known. With this information, he can usually already make a guess as to whether a sun allergy is present or not.
Photo provocation is usually used to confirm this assessment. A small area of skin is specifically irradiated with UV light in order to provoke the typical symptoms of a sun allergy. If skin reactions appear a few days later, a sun allergy is considered confirmed.
What to do if you have a sun allergy?
The surest way to avoid developing a sun allergy is to minimize exposure to the sun. Long sunbaths or other activities in the blazing sun are therefore not advisable. Of course, exposure to sunlight cannot be completely avoided . However, it is then important to gradually get the skin used to the sun so that the body does not immediately get an “overdose”. Many shorter periods outdoors are therefore better than long periods in early spring, as this gives the skin the opportunity to slowly get used to UV radiation. Once the habituation effect has set in, those affected usually suffer from significantly fewer symptoms.
Note:The adaptation of the skin is only temporary. If there is a prolonged period in which the skin does not come into contact with strong solar radiation, for example in winter, the hypersensitivity returns.
Consistent and conscientious sun protection is also important . A sunscreen should have at least a sun protection factor between 30 and 50. It is also advisable to ensure that it contains both UV-B and UV-A filters. Oil-free preparations with no artificial fragrances or preservatives are the best choice as they do not irritate the skin further.
Tip: Special UV protective films are ideal for long car journeys. They are attached to the windows and filter the UV-A rays, which could otherwise lead to skin problems even with the car windows closed.
The right clothing also plays an important role in sun protection. Tightly woven fabrics are less permeable to UV rays and should cover the most sensitive parts of the body. Long-sleeved clothing and a sun hat should not be missing.
If, despite all precautionary measures, a sun allergy occurs, the symptoms should be alleviated as much as possible. The first step is always to get out of the sun. Cold compresses help cool the skin and relieve itching. Antihistamines can also help with this. In the case of severe skin rashes, the doctor may prescribe cortisone-containing ointments or creams that have an anti-inflammatory effect. However, these are usually not suitable for children under the age of six.
If necessary, the doctor can also help to prevent the occurrence of a sun allergy. A so-called phototherapy can be used for this purpose. In this case, the skin is treated preventively with low-dose UV radiation. The intensity of the radiation is slowly increased over the course of the therapy so that the skin can get used to the sun’s rays. Such therapy is particularly useful before longer trips to sunny areas.
Note: Such phototherapy should not be carried out on your own in the solarium, as the effects cannot be controlled in this way.