Everyone knows sunburn – and the measures against it, too. But while you 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 in the summer is not nevertheless clouded, sun allergy sufferers should prepare themselves accordingly. How that goes, explains Prof. Dr. Eberhard Paul, owner of a dermatological practice in Nuremberg.
The skin of more and more people reacts allergically to the sun. Is there an explanation for this?
Prof. Paul: To answer the question accurately, we must first distinguish between the different types of sun allergy. We use the term “allergy” liberally, usually without knowing in detail the mechanism of the hypersensitivity reaction. Phototoxic reactions without a true allergic mechanism are certainly on the decline. These occur when certain light-sensitizing substances meet UV light – this includes, for example, Beloque dermatitis, which can also be triggered by perfume oils. Here, patient education has been successful. Another large group is the so-called Mallorca acne, which is very likely triggered by certain components in sun or skin creams and UVA. Majorca acne can also be caused by UVA tanning in solariums. The largest group of sun allergies, “polymorphous light dermatosis” has been known since 1878, but is increasing. More women than men are affected and the disease usually starts in young adults. It is not known exactly why this type of light allergy is increasing. The most severe form is “sun urticaria” – a form of hives triggered by sunlight, it is extremely rare but can lead to life-threatening shock with cardiovascular failure. Sufferers must be hospitalized immediately.
How can you recognize a sun allergy?
Typically, the skin changes do not occur immediately during sun exposure, but quite a few hours to two days afterwards. The name “polymorphic,” or “multiform,” skin disease indicates that the appearance is not always the same. The rashes vary from patient to patient and can range from pinhead- to pea-sized blisters to red nodules. They may be accompanied by excruciating itching that does not subside at night.
Is it possible to prevent sun allergy?
As already indicated, a meaningful prophylaxis is difficult, because the causes are not exactly known. In the case of Mallorca acne, it is very successful if emulsifier-free sunscreens are used. It is more difficult with polymorphous light dermatosis. What looks different in different patients also responds to quite different preventive measures. However, the following applies to all: Slowly get used to the sun and consistent light protection. This primarily means suitable clothing and sunscreens with UVA and UVB protection. Since consistent protection against UVA radiation is particularly important for sun allergy sufferers, brand-name products should be used, which can be purchased at pharmacies, for example. Cheap sun creams often only protect well in the UVB range, while UVA protection remains inadequate. This is what studies conducted by the University of Tübingen have shown.
What ingredients should a sunscreen for allergy sufferers contain?
It is favorable if the sun creams contain additional antioxidants, such as vitamin E.
What are the options for prophylaxis with medication?
In some people, prophylactic calcium administration a few weeks before expected sun exposure helps very well, but in others it does not help at all. With the intake of beta-carotene, here 30 mg a day should be taken, it behaves similarly. Some swear by it, others benefit only slightly. 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 tanning beds to get used to the sun. What should they be aware of?
In principle, prevention, in the sense of a kind of hardening against sun allergy, can be carried out by visiting the solarium. However, the prerequisite is the slow increase of the dose, i.e. the duration of stay on the tanning bed. At the beginning 5 minutes can be enough and 15 minutes should not be exceeded.For prevention, only those banks that emit UVA and UVB rays are suitable, since polymorphous light dermatosis is triggered by both types of radiation. Also, all cosmetics and skin care products must be removed before sun exposure. However, by judicious use of the natural sun, the skin can be accustomed to UV radiation. Patients suffering from very pronounced sun allergy with severe skin changes should undergo “hardening” under the supervision of a dermatologist. Here, the skin is gradually exposed to increasingly stronger UV radiation. Since this procedure is very costly, it should only be used in severe cases.
If it happened despite all precautions, how to treat sun allergy?
With light rashes and inflammation of the skin, itching often occurs first. By antihistamines as gels or tablets one can prevent worse already at the beginning. If severe skin changes have developed, a visit to the dermatologist is unavoidable. Corstisone ointments or tablets bring rapid relief. Since the cortisone only has to be given for a short time, no skin damage or severe side effects are to be expected.
What should be considered in skin care after sun exposure?
Creams with antioxidants, such as vitamin E are favorable, but you can not expect allergy prevention, because you can not block strong reactions with it. 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 mild sunburns. Thank you for the information, which will certainly help those affected.
