Symptoms of urticaria

In acute urticaria (usually caused by exposure to allergens), a few minutes after contact with the allergen, the patient develops erythema on the skin, then urticarial, intensely itchy elements of various sizes and bizarre shapes with ring-shaped hyperemia and clear boundaries appear. Urticaria is characterized by the absence of pigmentation after the disappearance of the elements.

The rash in acute urticaria is a monomorphic rash with an erythematous border. Sometimes the rash is similar to scarlet fever and measles. The disease begins acutely and is accompanied by severe itching of the skin. Hyperemic areas of the rash appear in places of itching. As the swelling of the papillary layer of the dermis increases, the papular elements turn pale. With exudation, elements in the form of bubbles are formed in the center of the papules, and swelling of the papillary layer also develops. The pathogenetic link is an increase in the permeability of the microcirculatory bed and the development of acute edema in the surrounding area. In urticaria, the capillaries of the subcutaneous tissue become permeable, along with this, vasodilation and slight eosinophilic infiltration are observed.

Often, skin swelling may change its intensity over several hours and be accompanied by severe itching. In some cases, a garland-like swelling and erythema with a pale sunken center may be seen. In addition to skin manifestations, abdominal syndrome may be observed with swelling of the gastrointestinal mucosa. It usually begins with nausea, vomiting, first food, then bile. Acute pain occurs, initially local, then spread throughout the abdomen, accompanied by flatulence with increased intestinal peristalsis. During this period, a positive Shchetkin-Blumberg symptom may be observed. The attack ends with profuse diarrhea. Abdominal swelling is combined with skin manifestations in 20-40% of cases. When the pathological process is localized in the urogenital tract, a picture of acute cystitis with acute urinary retention develops. Swelling of the genitals is accompanied by a corresponding clinical picture. Sometimes swelling of the joints, an increase in temperature from subfebrile to intermittent fever, headache, general malaise with symptoms of intoxication are noted.

Urticaria may acquire a hemorrhagic character due to the release of red blood cells from the vascular bed, which disintegrate in the surrounding tissue. The sizes of the rash elements vary - from several millimeters to tens of centimeters. They can be separately located or confluent. The preferred localization of the elements is on the extensor surfaces of the limbs, trunk and gluteal region. The duration of the acute period is from several hours to several days. Urticaria often recurs.

In a reaction to food, before the typical rash appears, the patient feels a tingling of the tongue, lips, palate, swelling in these areas, and often sharp pains in the abdomen. Often, conjunctivitis is observed, less often - difficulty breathing due to swelling of the larynx. Sometimes patients develop vomiting, collapse, anaphylactic shock. With food allergies, there may be perioral and perianal dermatitis.

Patients have a special type of dermographism - a rapid persistent papular reaction resembling the skin reaction to the introduction of histamine. Urticaria is often caused by insect bites, contact with plants, physical factors (delayed urticaria from pressure, solar urticaria, generalized and limited heat urticaria, cold urticaria), neurogenic causes.

Chronic urticaria is when the rash persists for more than 6 weeks. This course is typical for non-immune urticaria, urticaria in systemic diseases.

Complications of urticaria

Anaphylactic shock, laryngeal edema (croup), neurological disorders.