Simple chronic lichen: causes, symptoms, diagnosis, treatment

Simple chronic lichen (synonyms: limited neurodermatitis, limited neurodermatitis, limited atopic dermatitis, itchy lichenoid dermatitis, lichen Vidal, limited chronic simple prurigo).

The term neurodermatitis (syn: neurodermatitis) introduced Brocq in 1891 to refer to skin diseases in which skin changes develop as a result of scratching caused by primal itching.

Consequently, the primary itching is a characteristic symptom of neurodermatitis. The limited neurodermatitis is affected almost exclusively by adults. Men suffer from this form somewhat more often than women. Dermatologists often use the term limited neurodermatitis. Many dermatologists separate the limited neurodermatitis from atopic neurodermatitis not only by clinical manifestations, but also by etiology and pathogenesis.

[1], [2], [3], [4], [5]

What causes simple chronic lichen?

The main pathogenetic factor is the increased sensitivity of the skin to irritants, apparently due to the proliferation of nerve endings, and a predisposition to hyperplasia of the epidermis in response to a mechanical trauma. In the emergence of the disease, an important role is played by functional disorders of the nervous and endocrine systems, the allergic state of the organism, and diseases of the gastrointestinal tract. They also indicate hereditary predisposition.

Symptoms of a simple chronic lichen

The disease begins with an itchy skin. Symptoms of a simple chronic lichen are localized mainly on the posterior and lateral surfaces of the neck, in the popliteal and ulnar folds, in the anogenital region, on the inner thighs, in the interannual folds. But foci may appear on other parts of the skin, including the scalp. In the beginning, the skin in the areas of pruritus is not externally changed. Over time, under the influence of combs appear polygonal papules of dense consistency, sometimes covered with mucous scales. The papules merge and form oval or round plaques that are pink to brownish red. The skin thickens, becomes rough, the dermal drawing (lichenification) is expressed. At the height of the development of the disease, three zones are distinguished in the focus. Peripheral, or external, pigmentation zone surrounds the lesion in the form of a belt and usually the outer or inner boundaries are not clear. Medium, papular, the zone consists of nodular rashes of pale pink, grayish or yellowish color, the size of a pinhead to a small lentil. The papules are irregular in shape and are not sharply defined, almost do not rise above the surrounding skin. Their surface is thickened, smooth and as a result of combs often covered with a bloody crust. The inner zone is characterized by severe skin infiltration. Often, this zone is the only manifestation in the clinical picture of the disease.

Unreasonable and untimely treatment of candidiasis vulvovaginitis leads to a prolonged course of it, and the constant itching of the genital organs contributes to the development of lichenification. Patients with women may develop a limited neurodermatitis of the external genitalia. The author observed the development of limited neurodermatitis of the external genital organs after prolonged irrational treatment of vulvovaginal candidiasis.

In the practice of dermatovenereologist, the following atypical and rare varieties of limited neurodermatitis are common:

Depigmented neurodermatitis. With prolonged course of limited neurodermatitis, secondary hypopigmentation occurs (vitiligo-like changes). They believe that they appear as a result of scratching. It often gives the impression that there is a combination of two processes - neurodermatitis and vitiligo.

Hypertrophic (warty) neurodermatitis. In this form, against the background of a typical clinical picture of a limited neurodermatitis, there are separate nodular and even nodular eruptions, very similar to those with nodular pruritis. Such foci appear mainly on the inner surfaces of the thighs, they can also be localized to any other areas.

As a result of severe itching of the scalp, hair falls out, the skin becomes thinner, shines, but not atrophic, the process is not associated with the follicular apparatus. This form of the disease is called decalculating neurodermatitis.

The pointed follicular neurodermite is characterized by the follicularity of the rashes and their pointed form.

The linear neurodermatitis manifests itself in the form of fairly long bands of different widths of lichenification. Individual nodules are often much larger than with conventional limited neurodermatitis. Foci are more often localized on the extensor surfaces of the extremities.

Histopathology. In the epidermis, intracellular edema of the subulate cells, hyperkeratosis, parakeratosis, and acanthosis are noted. Spongia is weakly expressed. In the dermis, the papillae are swollen, elongated and dilated, the argyrophilic fibers thickened. The infiltrate consists of lymphocytes and a small number of fibroblasts and leukocytes, located mainly around the vessels of the papillary layer.

Treatment of a simple chronic lichen

Treatment of a simple chronic lichen consists of a thorough clinical and laboratory examination and elimination of identified co-morbid conditions, observance of a strict diet. From medications use psychotropic, weak antipsychotics, antihistamines (tavegil, fenistil, diazolin, etc.), externally - corticosteroids (betiovate, elokom, etc.) and itching (fenistil-gel, 1% dimedrol, 0.5- 2% anesthesic, 1-2% menthol) ointments. In torpid current, foci of triamcinolopa at a concentration of 3 mg / ml and impose occlusive dressings over the corticosteroid ointment.