Meadow grass dermatitis (dermatitis protensis, photodermatitis) is a skin inflammation caused due to certain extracts in plants and subsequent exposure to sunlight, which leads to severe pigmentation after healing.
What is meadow grass dermatitis?
Meadow grass dermatitis is an inflammatory skin condition and occurs primarily in spring through fall. Most often, contact with certain plants combined with sunlight are causative factors for meadow grass dermatitis. It mainly affects people who have a lot to do with plants or are frequently exposed to the sun. These include, for example, farmers or gardeners but also children who often spend time in the fresh air.
Causes
In meadow grass dermatitis, a phototoxic skin reaction occurs that is triggered by certain plant substances and UV light. These substances are mainly derived from so-called psoralenes, which are found in fruit stalks, stems, as well as leaves of exotic or native plants. These include celery (Apium graveolens), carrot, bergamot (Citrus bergamia), rue (Ruta gravedens), fig tree (Ficus carica) and angelica. However, masterwort (Peucedanum ostruthium), meadow hogweed (Heracleum sphondylium), Hercules perennial (Heracleum montegazzianum) and parsnip (Pastinaca) also promote inflammation of the skin. Some of the plants mentioned are also used for perfumes, spices or drinks, so that a phototoxic reaction can also be triggered in this way. In addition, meadow grass dermatitis can also be caused by the following drugs: Alendronate, specific nonsteroidal anti-inflammatory drugs, tetracyclines, phenothiazines, and 3,5- and 8-methoxypsoralen, respectively. In addition, meadow grass dermatitis may also be caused by cosmetics, tars, or acridine dyes. Photodermatitis is not based on allergy, therefore it can occur in any person. Moist skin also favors its occurrence. The plant substances that are considered to trigger meadow grass dermatitis are so-called photosensitizers. These substances can absorb UV light and transfer the energy produced to the skin. While sunburn is a radiation overdose, in phototoxic reactions, a UV dose that is within the tolerance range leads to dermatitis.
Symptoms, complaints, and signs
After contact with the plants, skin lesions appear after about one to two days and have a leafy, reticulated, or streaky appearance. Because of the greatly delayed onset of symptoms, the trigger is therefore often not recognized by those affected. Blisters form, and the skin is red and itchy. In addition, patients also frequently complain of burning pain. If the skin barrier is damaged, superinfection may also occur. If exposure to light is very weak after contact with the photosensitizers, meadow grass dermatitis often progresses without an inflammatory phase. This form is called photodermatitis pigmentaria. After about two to four weeks, the skin lesions heal with severe hyperpigmentation. In the case of photodermatitis due to cosmetics, hyperpigmentation often appears in the form of a descending drop. The skin pigmentation often disappears only after several months and can be cosmetically disturbing. Phototoxic reactions follow a specific distribution pattern, with the skin changes occurring specifically on exposed areas of skin. The most commonly affected areas of skin are the legs and arms. If the dermatitis is triggered by cosmetics, skin changes may also occur on the décolleté, neck as well as on the face. Sometimes a differentiation from the so-called aerogenic contact dermatitis, whose triggers are plant allergens, is relatively difficult. Certain photosensitizers such as chlorpromazine or coal tar also often elicit an immediate reaction with urticarial erythema, burning, and stinging.
Diagnosis and course of the disease
The physician makes the diagnosis based on the form of the skin manifestations. The blisters that appear, which often have very bizarre patterns, can also distinguish meadow grass dermatitis from sunburn. If necessary, the physician can also detect the photosensitizer by a photopatch test.In a photopatch test, the physician applies test substances to a patch and attaches it to the patient’s back. After one day, one side of it is removed and irradiated with UV light. After two days, the doctor also removes the other test patch and marks both areas with a pen. These areas are then evaluated for blisters, papules as well as redness.
Complications
In meadow grass dermatitis, the affected person primarily suffers from various skin complaints. These complaints thereby have a very negative effect on the aesthetics of the affected person and can thus also lead to inferiority complexes or to a significantly reduced self-esteem. Especially children suffer from depression or other psychological complaints, because they are often teased or bullied. As a result of meadow grass dermatitis, those affected suffer from severe itching and blisters on the skin. The skin itself is noticeably reddened and may also burn or hurt. Particularly at night, this pain can lead to difficulty sleeping and thus to irritability on the part of the patient. The patient’s quality of life is considerably reduced by the disease. Furthermore, there is a very strong pigmentation, which is also cosmetically disturbing. Especially on the face, the discomfort can be very unpleasant. The treatment of meadow grass dermatitis is carried out with the help of creams and ointments and in most cases leads to a positive course of the disease. As long as the affected person also avoids contact with the triggering substance, there are usually no particular complaints. The life expectancy of the affected person is not negatively affected by the disease.
When should one go to the doctor?
If changes in the skin appearance or health peculiarities occur during a stay outdoors, a visit to the doctor should take place to clarify the complaints. In many cases, the abnormalities show up about one to two days after contact with plants. Medical tests are needed to make a diagnosis and therefore a doctor should be consulted. If there is pain, the formation of blisters or redness of the skin, action is required. Any itching, general malaise or feeling of sickness should also be investigated and discussed with a physician. Difficulty sleeping, disturbances in concentration as well as behavioral problems indicate a health irregularity that would need to be clarified. A withdrawal from social life, mood swings, a lowered sense of well-being as well as the assessment of a reduced quality of life are signs of a health disorder. In order to initiate a relief of the symptoms and an improvement of the enjoyment of life, a clarification of the cause as well as a treatment plan is needed. If open wounds occur due to the itching, complications can arise. If these are not taken care of professionally, sepsis can occur, potentially endangering human life. Therefore, if existing irregularities increase in extent and intensity, a doctor should be consulted. A dry skin appearance as well as tension of the skin should also be interpreted as a warning signal of the organism and should be treated accordingly.
Treatment and therapy
Meadow grass dermatitis is treated locally with lotions and creams containing glucocorticoids. Very severe photodermatitis is treated like a second-degree burn. For this, the doctor punctures, cleans and disinfects the larger blisters and then protects them with a dressing. In addition, the redness is cooled like a sunburn. Phototoxic drugs as well as cosmetics must be discontinued immediately. A strong depigmentation can be achieved by a combination of hydrocortisone 1 percent, hydroquinone 5.0 percent as well as vitamin A acid 0.1 percent. If permanent hyperpigmentation occurs, laser therapy can provide relief. Patients should also avoid contact with the triggering plant substance. Furthermore, direct sunlight should be avoided for several days. In very severe forms, the doctor often also prescribes cortisone to be taken or infused.
Prevention
One can protect oneself from meadow grass dermatitis by wearing clothing that covers the legs and arms to prevent contact with the plant. Particular care should be taken during heavy sweating or after bathing, as the skin is damp and the effect of the plant substances is thus increased.Shade or cloudy skies, on the other hand, do not protect against meadow grass dermatitis, as there is still enough ultraviolet light to cause the skin condition.
Follow-up
Meadow grass dermatitis is an allergic disease. Affected individuals should be fully informed about the condition and know the circumstances under which the adverse health effects may occur. Medical tests can help the treating physician determine which plant substances the affected person reacts to. The patient should know plant locations and growing seasons to minimize personal risk. To take preventive action, certain regions can of course be avoided. Before traveling, it is helpful to inform oneself about the corresponding vegetation of the Urlausgebiet, in order to prepare oneself sufficiently. Exposure to UV radiation generally aggravates the symptoms of meadow grass dermatitis and may cause further complications. Therefore, sunlight should be avoided as much as possible at the first appearance of skin irregularities. When leaving the house, care should be taken to cover the body with appropriate clothing as much as possible. After a longer stay outdoors, it is advisable to change clothes in order to keep the pollen content in the air as low as possible. It is also important to carry your doctor’s prescribed medication with you during the growing and blooming season so that you can take immediate action if necessary. To prevent allergies, a diet rich in vitamins is very important. Especially vitamin C, which is found in peppers, savoy cabbage, kale and fennel, helps the body protect itself from allergies.
What you can do yourself
People with meadow grass dermatitis should fully educate themselves on how to manage the condition. It is important that they get to know sufficiently under which circumstances the health disorders occur and what effects their own behavior has. Various tests are used to find out to which plant substances the affected person reacts. Biological and geographical knowledge it important, in order to experience early the locations as well as the growth time of the appropriate plants. In many cases, after a certain period of time, sufficient knowledge is acquired about where the triggering plants are located. The region is avoided so that preventive action is taken. Before starting a trip or going to another area, the affected person should also try to get information about the fauna there. At the first irregularities, sunlight should be avoided. Exposure to UV radiation increases discomfort and can lead to further complications. Therefore, care should be taken to wear clothing that covers the body as best as possible when leaving the house. With the onset of the natural growing and blooming period, the medicine prescribed by the doctor should be carried as a precaution. Studies have shown that a balanced diet rich in vitamins also has a positive effect on further developments. Above all, care should be taken to ensure an adequate supply of vitamin A.
