Sun allergy – expert interview
Everyone knows sunburn  – and the measures against it too. But while one can avoid this direct effect of the sun’s rays on the skin, countermeasures for a “sun allergy” are more difficult. Already every 10th German suffers from this hypersensitivity to the sun. So that the joy of summer is not spoiled, people who are allergic to the sun should prepare accordingly. How this is done is explained by Prof. Dr. Eberhard Paul, owner of a dermatological practice in Nuremberg.
More and more people’s skin is allergic to the sun. Is there an explanation for this?
Prof. Paul: In order to answer the question precisely, one must first distinguish between the different types of sun allergy. We use the term “allergy” liberally, mostly without knowing the mechanism of the hypersensitivity reaction in detail. The phototoxic reactions  without a true allergic mechanism are certainly declining. These arise when certain light-sensitizing substances come into contact with UV light – this includes, for example, Beloque dermatitis, which can also be triggered by perfume oils. Patient education was successful here.
Another large group is the so-called Mallorca acne,  which is very likely to be triggered by certain components in sunscreen or skin creams and UVA. Mallorca acne can also be caused by UVA tanning in solariums.
The largest group of sun allergies, “polymorphic light eruptions” has been known since 1878, but is increasing. More women than men are affected and the disease usually begins in young adults. It is not exactly known why this type of light allergy is increasing.
The most severe form is “solar utricaria” – a form of hives  caused by sunlight , it is extremely rare but can lead to life-threatening shock  with cardiovascular failure. Those affected must go to the hospital immediately.
How do you recognize a sun allergy?
Typically, the skin changes do not appear immediately during exposure to the sun, but several hours to two days afterwards. The name “polymorphic”, i.e. “various” skin disease  shows that the appearance is not always the same. Rashes vary from patient to patient and can range from pinpoint to pea-sized blisters to red bumps. They can be accompanied by excruciating itching  that doesn’t go away at night.
Can you prevent sun allergy?
As already indicated, meaningful prophylaxis is difficult because the exact causes are not known. With Mallorca acne it is very successful if emulsifier-free sunscreens are used. It becomes more difficult with polymorphic light eruption. What looks different in different patients also responds to very different preventive measures. However, the following applies to all of them: get used to the sun slowly and use consistent sun protection. This primarily means suitable clothing and sunscreen with UVA and UVB protection.
Since consistent protection against UVA radiation is particularly important for people who are allergic to the sun, branded products that can be bought in pharmacies, for example, should be used. Cheap sun creams often only provide good protection in the UVB range, while the UVA protection remains inadequate. This has been shown by studies by the University of Tübingen.
What ingredients should a sunscreen for allergy sufferers contain?
It is beneficial if the sunscreen also contains antioxidants , such as vitamin E.
What are the options for drug prophylaxis?
For some people, prophylactic calcium a few weeks before expected sun exposure helps a lot, but for others it doesn’t help at all. The situation is similar with the intake of beta- carotene , 30 mg a day should be taken here. Some swear by it, others benefit little. According to studies from the USA, smokers should not take beta-carotene, as this can increase the risk of cancer.
Some sun allergy sufferers use solariums to get used to the sun. What is to be considered?
In principle, a visit to the solarium can be used as a form of prevention against sun allergies. However, the prerequisite is the slow increase of the dose, i.e. the length of time spent on the sunbed. In the beginning, 5 minutes can be enough and 15 minutes should not be exceeded. Only benches that emit UVA and UVB rays are suitable for prevention, since polymorphic light eruption is triggered by both types of radiation. In addition, all cosmetics and skin care products must be removed before sunbathing.
However, sensible exposure to the natural sun can also get the skin used to UV radiation. Patients who suffer from a very pronounced sun allergy with severe skin changes should undergo “hardening” under the supervision of a dermatologist. Here the skin is gradually exposed to ever greater UV stress. Since this procedure is very time-consuming, it should only be used in severe cases.
If it happened despite all precautions, how to treat sun allergy?
In the case of light rashes and inflammation of the skin, itching often occurs first. Antihistamines  in the form of gels or tablets can prevent worse from happening right from the start . If severe skin changes have developed, going to the dermatologist is unavoidable. Cortisone ointments or tablets provide rapid relief. Since the cortisone  only has to be given for a short time, no skin damage or serious side effects are to be expected.
What should you consider when taking care of your skin after the sun?
Creams with antioxidants, such as vitamin E  , are cheap, but you cannot expect allergy prevention because you cannot block strong reactions with them. Nevertheless, so-called after-sun preparations or lotions with vitamins A  and E and the skin-soothing active ingredient panthenol can have a soothing effect on light sunburns.
