Hives

Urticaria is an allergic disease characterized by the formation of blisters on the skin and mucous membranes.

Etiology, pathogenesis. The etiological factors that determine the development of urticaria are divided into exogenous (physical-temperature, mechanical, chemical, etc.) and endogenous (pathological processes in internal organs, disorders of the nervous system). In all cases, pathogenesis has many common links. Etiological factors cause the accumulation in the tissues of chemically active substances such as histamine, which increase the permeability of the vascular walls, expand the capillaries, resulting in the edema of the papillary layer of the dermis, which causes the appearance of blisters.

The role of allergens can be played by incompletely split protein products that have not yet lost specificity (penetrating into blood flow, they induce the production of antibodies to a certain food product), toxins (spoiled foods, incompletely digested), toxic substances formed in colitis, insufficient kidney function. Possible bacterial allergy. An important role in the pathogenesis of urticaria is played by functional disorders of the nervous system, especially the vegetative. In particular, cholinergic urticaria is known, which develops with nervous excitation and is caused by the release of acetylcholine in tissues under the influence of irritation of the parasympathetic nervous system,

The clinical picture of urticaria is characterized by the formation on the skin (less often mucous membranes) of exudate endless ephemeral elements - blisters, swollen, dense, bright pink, rising above the skin, various sizes (0.5 to 10-15 cm in diameter) and outlines Rounded, coarse-grained, etc.), often with a zone of blanching in the center. Blisters disappear (sometimes in a few minutes) without a trace.

Acute urticaria is characterized by a sudden onset, the appearance of severe itching, burning and rashes on any areas of the skin, as well as on the mucous membranes of the lips, tongue, soft palate, larynx. Blisters can be of different sizes and shapes, perhaps their fusion, accompanied by a violation of the general condition (nettle fever, arthralgia). Acute urticaria is more often due to drug or food allergy, parenteral administration of drugs, serums, vaccines, blood transfusions.

Acute limited edema Quincke (giant urticaria) is also characterized by the sudden development of limited edema of the skin (mucous membrane) and subcutaneous fatty tissue of the face (lips, cheeks, eyelids, etc.) or genitalia. Thus the skin becomes densely elastic, white, less often pink. Subjective sensations are usually absent. After a few hours or 1-2 days, the swelling subsides. A combination of Quincke's edema with a common urticaria is possible. With edema developing in the larynx, stenosis and asphyxia are possible.

Chronic recurrent urticaria usually develops against a background of prolonged sensitization caused by foci of chronic infection (tonsillitis, cholecystitis, adnexitis, etc.), a violation of the gastrointestinal tract, liver, etc. Recurrences of the disease characterized by the appearance of blisters in various areas of the skin are replaced by remissions Of different duration. During an attack, headache, weakness, fever, arthralgia, swelling of the gastrointestinal mucous membrane - nausea, vomiting, diarrhea are possible. An excruciating itch can be accompanied by insomnia, neurotic disorders.

Solar urticaria is a type of photodermatosis; Develops in persons suffering from liver disease and impaired porphyrin metabolism with pronounced sensitization to ultraviolet rays. Women are more often sick. The disease is characterized by the appearance of rashes on open areas of the skin (face, hands, etc.). Typical seasonality (spring-summer). With prolonged exposure to the sun, rashes may be accompanied by a general reaction of the body in the form of a violation of breathing and cardiac activity, a shock is possible.

The diagnosis in typical cases is not difficult. Differential diagnosis is carried out with Dühring dermatosis, for which, in addition to the urticar elements, vesicles and papules are characteristic.

Treatment. In acute urticaria caused by ingestion of medicinal and nutritional substances, laxatives, hyposensitizing drugs - 10% solution of calcium chloride IV, calcium gluconate w / m, antihistamines, are indicated. In severe cases, an attack can be suppressed by the administration of SC with 1 ml of epinephrine, corticosteroids (with a threatening laryngeal edema it is better to inject IV). External - antipruritic means: 1% alcohol solution of menthol, salicylic acid, calendula.

With chronic urticaria it is necessary to identify the etiologic factor. In case of detection of allergen, specific hyposensitization, sanation of foci of chronic infection, treatment of gastrointestinal tract diseases, dehelminthization are shown. With disorders of the nervous system, sedative therapy. It is recommended that a milk-vegetable diet with exclusion of stimulants. General ion-galvanization with calcium chloride and sub-aqua baths are also shown. In the case of solar urticaria, photo-desensitizing drugs (delagil, plakvenil).

Prevention. Treatment of foci of chronic infection, diseases of the gastrointestinal tract, nervous system, elimination of repeated exposure to allergens.