Polymorphous light dermatosis is a photodermatosis. The skin condition is common.
What is polymorphous light dermatosis?
Polymorphous light dermatosis represents the most common skin condition caused by sunlight. It is also popularly referred to as sun allergy or light allergy, but this is incorrect because these terms do not even exist in medicine. With a share of about 90 percent, polymorphic dermatosis is the most common disease of this type. About 10 to 20 percent of the population suffer from it. The female sex is particularly affected by the skin complaints. But the so-called sun allergy is also often seen in children and young adults. In the last years an increasing tendency could be registered. Polymorphous light dermatosis is not an allergy in the classical sense, because typical immune reactions and the formation of antibodies are absent. In Germany, polymorphic dermatosis reaches its greatest prevalence in the months of March to June, which is due to the climatic conditions. However, traveling to areas where the sun shines frequently, photodermatosis can occur at any time.
Causes
The exact causes of polymorphous photodermatosis are still not well understood. What is known at least is that it is not an allergy, although the symptoms of photodermatosis resemble it. Polymorphous light dermatosis is always triggered by unusually intense UV-A rays or UV-B rays. In most cases, this occurs during the vacation season due to over-extensive sunbathing. In 75 percent of all affected individuals, UV-A radiation is responsible for the onset of symptoms. In 10 percent, polymorphous light dermatosis is caused by UV-B radiation. The other 15 percent suffer from a combination of both forms of radiation. Some scientists are of the opinion that polymorphous light dermatosis is caused by the immune system. Thus, there is said to be a light-sensitive sensor in the skin cells that triggers the photodermatosis. In contrast, other researchers believe there is a dysbalance between oxidants and antioxidants within the horn-forming cells in the epidermis. This imbalance causes affected individuals to be more sensitive to solar radiation. Sometimes polymorphous light dermatosis is also caused by taking certain medications.
Symptoms, complaints, and signs
The typical symptoms of polymorphous light dermatosis usually appear with a delay. Thus, symptoms such as itching, burning, and reddish spots on the skin do not appear until several hours or even days after exposure to the sun. In addition, nodules, blisters or larger blisters form. In some affected individuals, the skin also swells. The symptoms of polymorphous light dermatosis present themselves differently in each individual. Thus, in some patients the redness may be pronounced, while others suffer from considerable itching. If a sun allergy occurs repeatedly, the symptoms are usually equally pronounced. Often the symptoms of polymorphous light dermatosis appear after a longer period of absence of the skin from the sun. Therefore, it mostly occurs in spring or during visits to the beach. It is typical that the symptoms appear exclusively on skin areas that have been exposed to intensive sunlight. Particularly affected skin areas are the face, neck, décolleté, hands, arms and legs.
Diagnosis and course of the disease
If polymorphous light dermatosis appears repeatedly, it is advisable to consult a physician. This deals first with the medical history of the patient. In doing so, he wants to know about the course of the skin problems and on which occasions they occur. In this way, he will obtain valuable information for making the diagnosis. Furthermore, other possible reasons for the skin complaints must also be ruled out. Possible triggers include photoallergic eczema or insect bites. For a reliable diagnosis, the physician irradiates a specific area of the skin with UV light. This may be the upper arm, for example. If a polymorphous light dermatosis is responsible for the complaints, the typical symptoms are triggered by this photoprovocation. Normally, the symptoms of a polymorphous light dermatosis go away on their own after a few days without leaving any traces on the skin.For this, however, the skin must not be exposed to further UV radiation. If the skin has regular contact with the sun, it becomes accustomed to the sun’s rays over time. As a result, polymorphous photodermatosis eventually weakens so that skin reactions no longer occur. If it is a chronic photodermatosis, however, its reoccurrence must be expected the following year.
Complications
In this disease, affected individuals suffer from various skin complaints. These affect thereby primarily very much on the aesthetics of the patient and can affect these negatively. Furthermore, inferiority complexes or decreased self-esteem may occur in this case. Children in particular may suffer from bullying or teasing in this condition and may also develop depression or other psychological complaints as a result. The patient’s quality of life is significantly reduced due to the disease. On the skin, the main symptom is a burning itch. Scratching can additionally lead to bleeding or to scars. Blisters and pustules can also form on the skin and make everyday life more difficult. Furthermore, patients with this disease suffer from sun allergy, so that the affected person usually has to protect himself from the sun. The risk of skin cancer is also significantly increased, so that those affected are dependent on regular checks and examinations. The treatment of the disease is symptomatic. Most of the symptoms can be alleviated acutely. Furthermore, treatment with the help of medication can also significantly limit and reduce the symptoms. Complications do not usually occur in this case.
When should one go to the doctor?
If affected individuals experience changes in the appearance of their skin when exposed to sunlight, they should see a doctor. If irregularities occur after sunbathing or a long walk, clarification of the symptoms is recommended. If skin abnormalities already develop at moderate temperatures and a stay of a few minutes in the sun, the observations should be discussed with a doctor immediately. Redness, pustules, swellings or the formation of spots should be examined and treated. If there is a burning sensation on the skin, unpleasant itching, or blistering, a doctor should be consulted. If there are nodules or changes in the usual pigmentation, a visit to the doctor is advised. Sterile wound care is required for open wounds. If this cannot be ensured to a sufficient degree, a visit to the doctor must be made. Otherwise, there is a risk of blood poisoning, as germs and other pathogens can enter the organism. This exposes the affected person to a life-threatening situation that should be avoided. If additional emotional or mental problems arise due to the visual changes, a doctor is also needed. In case of shame, withdrawal behavior, weepiness or depressive phases, help should be sought. In addition to a visit to the doctor, it is recommended to consult a therapist so that the general state of health improves as quickly as possible.
Treatment and therapy
To treat the discomfort caused by polymorphous light dermatosis, cooling the skin with yogurt, curd or buttermilk is recommended. Cooling causes the blood vessels to contract, which brings down possible swelling. Furthermore, the skin receives much-needed moisture, which promotes its regeneration. If the sun allergy is severe, the use of medication can be useful. For example, antihistamines administered as tablets or ointments have a soothing effect on itching. Preparations containing cortisone are sometimes also administered to combat the inflammation on the skin. Additional phototherapy is considered helpful. This takes place in spring or before a vacation trip and serves to gradually accustom the skin to the sun through irradiation. In this process, the UV radiation exposure is continuously increased.
Prevention
To prevent polymorphous light dermatosis from occurring in the first place, adequate protection from the sun should be provided. This includes sunscreen with a sun protection factor between 30 and 50, protective clothing, and wearing a hat.
Aftercare
In acute cases, polymorphous light dermatosis can be treated with special creams or ointments.These creams should contain corticosteroids such as hydrocortisone. Very severe itching after sunbathing can also be improved by taking antihistamines. To prevent the symptoms of polymorphous lichdermatosis, people with sensitive skin should slowly and gradually increase their exposure to UV radiation in spring and summer. It is especially advisable to do this weeks before the summer vacation, so that the skin can slowly get used to the sun radiation. It is also possible to protect oneself during sun exposure with broad-spectrum sun creams as a prophylaxis against the disease. These should be effective against both UVA and UVB rays and have the highest possible sun protection factor. Preparations containing the antioxidant alpha-glucosylrutin are also effective. Also, according to scientific studies, taking supplements such as vitamin D3 in the form of omega-3 fatty acids can improve the symptoms of polymorphous light dermatosis. Prophylactic phototherapy can also prevent the development of a sun allergy. This involves repeated whole-body irradiation with blue light of a specific wavelength. A very last step and a not recommended way of treatment is a so-called photochemotherapy. However, this therapy can cause long-term health risks in the patient.
What you can do yourself
In most cases, the rashes and wheals that develop in polymorphous light dermatosis heal without problems, but they are still unsightly and annoying, sometimes even painful. Therefore, the patient’s main concern will be to avoid UV-A light in order to prevent the condition from developing in the first place. Creams and lotions with a high level of sun protection also help to prevent the development of the wheals. If a rash does develop, the affected person can cool the areas. If possible, the areas should not be scratched open so that the pustules cannot become infected with bacteria. Antihistamines and phototherapy help to prevent further rashes. In particularly severe cases, the quality of life of those affected suffers considerably. Therefore, psychotherapeutic treatment is advised in similarly severe cases. Affected individuals also benefit from relaxation techniques. Progressive muscle relaxation according to Jacobson, yoga, qigong and tai chi are recommended. Music therapy can also provide some relief. Self-help groups for people with polymorphous light dermatosis did not exist for a long time. Only in recent years, when the disease became more frequent, self-help groups for light allergy sufferers were established. The first of these was the “Lichtblick” group in Schwerte, and other groups followed.
