Allergic dermatoses

Acute allergic diseases of the skin include urticaria, edema Quincke, toxicermia, multiforme, exudative erythema, Stevens-Johnson syndrome, Lyell's syndrome. These diseases are characterized by damage to the skin, mucous membranes, internal organs with the possible development of life-threatening conditions that require urgent intensive therapy. These forms of allergic dermatoses are characterized by acute diffuse or localized skin lesion with an itch of different intensity, a tendency to recurrence and chronic course.

Toxidermy

Toxidermy is an acute allergic skin disease that develops in children with increased sensitivity to food and drug allergens, and makes up 5-12% of allergic dermatoses.

The main sign of toxemia is a polymorphic rash of spotted-papular and bubbly nature, primarily on the extensor sides of the extremities, on the dorsal surfaces of the hands, feet. The elements of the rash have different shapes, the diameter does not exceed 2-3 cm. The mucous membranes of the oral cavity, genital organs can also be affected. The rash sometimes accompanies subfebrile temperature, pain in the joints and muscles, in severe cases - intoxication in the form of anorexia, lethargy and adynamic syndrome. There is a dermal itch, the intensity of which is high, especially in the period of acute inflammatory rashes. Itching is worse at night, but also during the day it is quite intense, can lead to insomnia and psychoemotional stress. Toxidermia can be combined with edema of the face, hands and feet. After the extinction of the rash, persistent pigmentation and peeling are noted.

Multiforme exudative erythema

Multiforme exudative erythema is a severe form of allergodermatosis in children. This acute recurrent disease with hereditary predisposition, IgE-dependent mechanism of formation. It occurs mainly at the age of 1 to 6 years. The disease is a polyethological syndrome of hypersensitivity. Called bacterial, primarily streptococcal, and drug sensitization, there are data on the role of viral infection in the development of the disease. It often occurs with exacerbation of tonsillitis, sinusitis, or other infectious diseases. Eruptions are accompanied by subfebrile temperature, intoxication syndrome. Multi-form exudative erythema manifests itself in the form of erythematous rashes on the skin and mucous membranes. Rashes are localized mainly on the trunk and extremities. Rashes can persist up to 2-3 weeks. There are three pathohistological types of lesions: dermal, mixed dermoepidermal and epidermal. In blood tests, leukocytosis, an increase in ESR, increased activity of transaminases and alkaline phosphatase are noted.

Stevens-Johnson Syndrome

Stevens-Johnson syndrome is the most severe form of allergic dermatosis in children. The main triggers of the disease are medications, usually antibiotics, analgin, aspirin. The disease begins acutely with fever to febrile numbers. The syndrome of intoxication, muscle pains is characteristic. The skin of the face, neck, limbs and trunk is affected. In the period of acute inflammatory eruptions, exudative-infiltrative epidermodermal formations of a rounded form of red appear. Grouping the rash is irregular and unsystematic. Rashes are characterized by itching. Burning, soreness, a feeling of tension. An obligatory component of this syndrome is erosion with elements of necrosis on the mucous membranes of the mouth and urinary tract. Mark bullous elements, Nikolsky's symptom is negative. In especially severe cases, gastrointestinal bleeding occurs. In the general analysis of the blood, leukopenia, anemia, in urinalysis - leukocyturia, erythrocyturia are revealed. In biochemical analyzes, the appearance of C-reactive protein, an increase in the activity of transaminases, amylase and alkaline phosphatase, hypercoagulation and platelet activation are noted. Diagnosis of the syndrome is based on severe current, the development of bullous elements and damage to the mucous membranes. Relatively rare are the toxic lesions of the parenchymal organs.

Lyell's Syndrome

Lyell's syndrome is the most severe variant of allergic bullous dermatitis, the mortality rate is up to 25%. This disease can develop at any age. The reason, as a rule, is the use of drugs, and especially antibiotics, more often when combined with several antibiotics at the same time. The initial manifestations resemble the multiforme exudative erythema, which are replaced by the formation of large flat blisters. In some areas of the skin, the epidermis is removed without a visible preceding bullous reaction under the influence of light pressure or touch (a positive symptom of Nikolsky). On the site of the opened bubbles, extensive erosive surfaces of bright red color are exposed. At the time of infection, the development of sepsis is observed very quickly. There may appear hemorrhages followed by necrosis and ulceration. Possible damage to the mucous membranes of the eyes with ulceration of the cornea, leading to visual impairment, cicatricial changes in the eyelids. Bladder-erosion, deep cracks with purulent-necrotic plaque can also appear on the mucous membranes of the mouth, nasopharynx, and genitals.

There may be toxic or toxic-allergic lesions of the heart in the form of focal or diffuse myocarditis, lesions of the liver, kidneys, intestines. Affected small vessels of the type of vasculitis, capillaritis, nodular periarteritis. A symptom of intoxication, hyperthermia, anorexia is expressed. The severity of the condition depends on the area of the skin. If more than 70% of the skin is affected, the condition is assessed as extremely difficult with a life threat, note vital disturbances associated with the phenomena of toxic edema of the brain, arrhythmia of the breathing, small cardiac output syndrome. Laboratory tests reveal anemia), neutropenia, lymphopenia, an increase in ESR up to 40-50 mm / h, hypoproteinemia, C-reactive protein, increased activity of alkaline phosphatase, transaminase and amylase. Characterized by electrolyte disorders, hypokalemia and hypercalcemia. There are violations of hemostasis in the form of hypercoagulation and a decrease in fibrinolytic activity with possible development of DIC syndrome.

Treatment of allergic dermatoses

Urgent therapy of allergic dermatoses should be only etiopathogenetic. It is necessary to establish a connection between the manifestation of the disease and the exposure of a causally significant allergen. The elimination of the allergen should be as complete as possible, while the possibility of its latent presence as a component in other food products and cross-reacting should be taken into account.

Of great importance is the conduct of enterosorption using povidone (enterodesis), lignin hydrolyzed (polyphepan), calcium alginate (algithorba), smecta and enterosgel.

The most effective anti-inflammatory drugs are glucocorticosteroids, which are shown in both acute and chronic phases of allergic dermatoses. Currently, various topical steroids are used in the form of cream, ointment [methylprednisolone aceponate (advantan), mometasone furoate] with short intermittent courses.

An obligatory component of treatment of severe forms of allergic dermatoses is local antibacterial agents. The necessary stage is the removal in the sterile conditions of the destroyed epidermis and the release of erosion from the crusts, washing and treatment of wound surfaces to prevent infection and the development of septic complications. On erosive surfaces, it is advisable to apply the mixture of topical corticosteroids, anesthetics, keratoplastic and anti-inflammatory agents with care. For this purpose, topical steroids are used in combination with actovegin or solcoseryl. Apply topical drugs that have minimal side effects while maintaining a high degree of anti-inflammatory effect. Preference is given to glucocorticosteroid preparations of the last generation - methylprednisolone aceponate (advantan) and mometasone furoate (elokom). These drugs exist in the form of creams, ointments, oily ointments and emulsions.

Modern systemic therapy of allergic dermatoses in children involves the appointment of antihistamines. In the acute period to obtain a rapid effect, parenteral administration of antihistamines of the first generation (clemastine, chloropyramine intramuscularly at the age of dosage) is necessary. With decreasing severity, it is better to use antihistamines of a new generation (loratadine, cetirizine, ebastin, desloratadine, fexofenadine).

Oral and parenteral administration of glucocorticosteroids is indicated in children with severe gradient course of allergic dermatoses and with insufficient effectiveness of local treatment with glucocorticosteroids. The duration of administration of systemic glucocorticosteroids should not exceed 7 days.

In children with allergic dermatoses, secondary skin infections caused by mixed flora are often observed. In such cases, the most optimal preparations containing 3 active ingredients: steroid, antibacterial and antifungal. This group includes a triderm, consisting of 1% clotri-mazol. 0.5% betamethasone dipropionate, 0.1% gentamycin sulfate.

In Lyell's and Stevens-Johnson's syndrome, an infusion of albumin at a rate of 10 ml / kg with the use of drugs improving the microcirculation of pentoxifylline (trental, agapurin)], disaggregants [ticlopidine (ticlid)] and anticoagulants (heparin) was shown. Intravenously prednisolone 5 mg / kg. Inosine (riboxin), pyridoxine, ascorbic, pantothenic and pangamic acids are also used to enhance the bicarbonate buffer system. In particularly severe cases with Stevens-Johnson and Lyell syndromes, a constant infusion of heparin from a calculation of 200-300 U / kg is recommended. In severe cases, with ineffectiveness of the above step therapy, especially with a large area of skin lesions, the appearance of new blisters and the growth of tissue necrosis, plasmapheresis is indicated. An essential component of the treatment of allergic dermatoses is anesthesia and sedation. In these cases, the use of diazepam (seduxen), sodium oxybate, omepon, promedol, ketamine, causing dissociated anesthesia is indicated.

[1], [2], [3], [4], [5], [6]