Meadow grass dermatitis

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Classification according to ICD-10
L56 Other acute skin changes caused by ultraviolet rays
L56.0 Phototoxic reaction to drugs
L56.1 Photoallergic reaction to drugs
L56.2 Phototoxic contact dermatitis,
berloque dermatitis
L56.3 Urticaria solaris
L56.4 Polymorphic photodermatosis
L56.8 Other specified acute skin changes from ultraviolet rays
L56.9 Acute skin changes caused by ultraviolet rays, unspecified
ICD-10 online (WHO version 2019)

The Phytophotodermatitis or photodermatitis (specifically phytophotodermatitis ) is an inflammation of the skin caused by certain plant extracts ( furanocoumarins ) and subsequent irradiation with UV-A is caused. In contrast to sunburn , the disease is prolonged and causes strong pigmentation after it has healed.

frequency

The disease occurs mainly in the period from early summer to autumn. Affected are people who occupy themselves with plants for work or in their free time and are then exposed to the sun. People of all skin types can be affected regardless of the level of previous tan.

Disease mechanism

Meadow grass dermatitis is a phototoxic skin reaction. The skin comes into contact from outside (or rarely via the bloodstream) with a photosensitizer , which absorbs the light energy and transfers it to neighboring molecules. The wavelengths of the triggering light are in the UV-A range or in the visible range.

Triggering substances

Giant hogweed or Hercules shrub

Most of the triggering substances come from the group of psoralens ( furocoumarins ) and are contained in leaves, stems and fruit bunches of native or exotic plants. Which includes:

Some of these plants are also used in beverages ( herbal liqueurs ), spices or perfumes and can also trigger a phototoxic reaction in this way.

Photosensitizers are also found in coal tar , and certain drugs can trigger photodermatitis:

clinic

Blistering after contact with rue ( Ruta graveolens )

One to two days after plant contact and exposure to the sun, skin changes are found in striped, leaf-shaped or net-like patterns, corresponding to the contact points with the plants or their cut surfaces. In addition, the necessary exposure to sunlight causes it to spread on the body - typically on the arms and legs. There will be redness and blisters that will peak after about three days. Patients report itching and burning pain. With severe hyperpigmentation, the skin symptoms heal after two to four weeks.

If the exposure to the sun is only weak, the strong inflammatory reaction may be absent and hyperpigmentation may occur immediately after one to two weeks ( photodermatitis pigmentaria or berloque dermatitis ).

Diagnosis and differential diagnosis

The streaky arrangement and the shape of the skin manifestations with reddening and blistering enable the diagnosis and the differential diagnosis to sunburn .

In contrast to Porphyria cutanea tarda , the porphyrin values ​​are normal.

therapy

Treatment is done locally with creams and lotions that contain glucocorticoids . In severe cases, systemic glucocorticoid administration can also provide relief. Prostaglandin synthesis inhibitors are ineffective.

forecast

The disease heals after two to four weeks and leaves a strong hyperpigmentation that can persist for many months. The treatment - apart from the acute symptoms - has no significant influence on the course.

Literature and Sources

  • Ernst G. Jung (Ed.): Dermatology. 2nd, revised and expanded edition. Hippokrates-Verlag, Stuttgart 1991, ISBN 3-7773-1021-2 .

Individual evidence

  1. ↑ NS Heskel, RB Amon, FJ Storrs, CR White: Phytophotodermatitis due to rue. In: Contact Dermatitis. Volume 9, No. 4, 1983, pp. 278-280.