Allergodermatoses

Acute allergic skin diseases include urticaria, Quincke's edema, toxicoderma, erythema 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 requiring urgent intensive care. These forms of allergic dermatoses are characterized by acute diffuse or localized skin lesions with itching of varying intensity, a tendency to relapse and chronic course.

Toxicoderma

Toxicoderma is an acute allergic skin disease that develops in children with increased sensitivity to food and drug allergens, and accounts for 5 to 12% of all allergic dermatoses.

The main symptom of toxicoderma is a polymorphic rash of a maculopapular and vesicular nature, primarily on the extensor surfaces of the limbs, on the dorsal surfaces of the hands and feet. The rash elements have different shapes, the diameter does not exceed 2-3 cm. The mucous membranes of the oral cavity and genitals can also be affected. The rash is sometimes accompanied by subfebrile temperature, pain in the joints and muscles, in severe cases - intoxication in the form of anorexia, lethargy and adynamic syndrome. There is skin itching, the intensity of which is high, especially during acute inflammatory rashes. The itching intensifies at night, but can also be quite intense during the day, can lead to insomnia and psychoemotional stress. Toxicoderma can be combined with swelling of the face, hands and feet. After the rash subsides, persistent pigmentation and peeling are noted.

Erythema multiforme exudative

Erythema multiforme exudative is a severe form of allergic dermatoses in children. This is an acute recurrent disease with a hereditary predisposition, IgE-dependent mechanism of formation. It occurs mainly at the age of 1 to 6 years. The disease is a polyetiological hypersensitization syndrome. It is caused by bacterial, primarily streptococcal, and drug sensitization; there is evidence of the role of viral infection in the development of the disease. It often occurs during exacerbation of tonsillitis, sinusitis or other infectious diseases. The rash is accompanied by subfebrile temperature, intoxication syndrome. Erythema multiforme exudative manifests itself in the form of erythematous rashes on the skin and mucous membranes. The rash is localized mainly on the trunk and limbs. The rash can persist for up to 2-3 weeks. There are three pathohistological types of lesions: dermal, mixed dermoepidermal and epidermal. Blood tests show leukocytosis, increased ESR, increased activity of transaminases and alkaline phosphatase.

Stevens-Johnson syndrome

Stevens-Johnson syndrome is the most severe form of allergic dermatosis in children. The main triggers of the disease are drugs, usually antibiotics, analgin, aspirin. The disease begins acutely with an increase in temperature to febrile numbers. Intoxication syndrome and muscle pain are characteristic. The skin of the face, neck, limbs and trunk is affected. During the period of acute inflammatory rashes, exudative-infiltrative epidermodermal formations of a rounded red color appear. The grouping of the rash is irregular and unsystematized. The rash is characterized by itching, burning, pain, a feeling of tension. An obligatory component of this syndrome is erosion with necrotic elements on the mucous membranes of the mouth and genitourinary tract. Bullous elements are noted, Nikolsky's symptom is negative. In especially severe cases, gastrointestinal bleeding occurs. A general blood test reveals leukopenia and anemia, while urine tests reveal leukocyturia and erythrocyturia. Biochemical tests reveal the appearance of C-reactive protein, increased activity of transaminases, amylase and alkaline phosphatase, hypercoagulation and activation of platelets. The diagnosis of the syndrome is based on the severe course, development of bullous elements and damage to the mucous membranes. Toxic damage to parenchymatous organs is observed relatively rarely.

Lyell's syndrome

Lyell's syndrome is the most severe form of allergic bullous dermatitis, with a mortality rate of up to 25%. This disease can develop at any age. The cause is usually the use of drugs, primarily antibiotics, often with a combination of several antibiotics at the same time. Initial manifestations resemble multiform 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 (positive Nikolsky symptom). At the site of the opened blisters, extensive erosive surfaces of a bright red color are exposed. When an infection occurs, sepsis develops extremely quickly. Hemorrhages may appear with subsequent necrosis and ulceration. Damage to the mucous membranes of the eyes with ulceration of the cornea is possible, leading to visual impairment, cicatricial changes in the eyelids. Blisters-erosions, deep cracks with purulent-necrotic plaque may also appear on the mucous membranes of the mouth, nasopharynx, and genitals.

Toxic or toxic-allergic heart lesions may join in the form of focal or diffuse myocarditis, liver, kidney, and intestinal lesions. Small vessels are affected by vasculitis, capillaritis, and nodular periarteritis. Symptoms of intoxication, hyperthermia, and anorexia are expressed. The severity of the condition depends on the area of skin damage. If more than 70% of the skin is affected, the condition is assessed as extremely severe with a threat to life; vital disorders associated with toxic cerebral edema, respiratory arrhythmia, and low cardiac output syndrome are noted. Laboratory tests reveal anemia, neutropenia, lymphopenia, increased ESR to 40-50 mm/h, hypoproteinemia, C-reactive protein, increased activity of alkaline phosphatase, transaminases, and amylase. Electrolyte disturbances, hypokalemia, and hypercalcemia are characteristic. Hemostasis disorders in the form of hypercoagulation and decreased fibrinolytic activity with the possible development of DIC syndrome are noted.

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 to the causative allergen. The exclusion of the allergen should be as complete as possible, while taking into account the possibility of its hidden presence as a component in other food products, as well as cross-reaction.

Of great importance is the implementation of enterosorption using povidone (enterodesis), hydrolytic lignin (polyphepan), calcium alginate (algisorb), smecta and enterosgel.

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

An obligatory component of the treatment of severe forms of allergic dermatoses is local antibacterial agents. A necessary stage is the removal of the destroyed epidermis under sterile conditions and the release of erosions from crusts, washing and treatment of wound surfaces to prevent infection and the development of septic complications. It is recommended to carefully apply a mixture of topical corticosteroids, anesthetics, keratoplastic and anti-inflammatory agents to the erosive surfaces with an applicator. For this purpose, topical steroids are used in combination with actovegin or solcoseryl. Topical drugs are used that have minimal side effects while maintaining a high degree of anti-inflammatory action. Preference is given to the latest generation of glucocorticosteroid drugs - methylprednisolone aceponate (advantan) and mometasone furoate (elocom). These products exist in the form of creams, ointments, fatty ointments and emulsions.

Modern systemic therapy of allergic dermatoses in children involves the administration of antihistamines. In the acute period, to obtain a quick effect, parenteral administration of first-generation antihistamines is necessary (clemastine, chloropyramine intramuscularly in an age-appropriate dosage). When the severity decreases, it is better to use new-generation antihistamines (loratadine, cetirizine, ebastine, desloratadine, fexofenadine).

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

Children with allergic dermatoses often have secondary skin infections caused by mixed flora. In such cases, the most optimal drugs are those containing 3 active components: steroid, antibacterial and antifungal. This group includes Triderm, consisting of 1% clotrimazole, 0.5% betamethasone dipropionate, 0.1% gentamicin sulfate.

In Lyell's syndrome and Stevens-Johnson syndrome, albumin infusion at a rate of 10 ml/kg is indicated with the use of drugs that improve microcirculation (pentoxifylline (trental, agapurin)], disaggregants [ticlopidine (ticlid)] and anticoagulants (heparin). Intravenous prednisolone 5 mg/kg. Inosine (riboxin), pyridoxine, ascorbic, pantothenic and pangamic acids are also used to enhance the bicarbonate buffer system. In especially severe cases of Stevens-Johnson and Lyell's syndromes, continuous heparin infusion at a rate of 200-300 U/kg is recommended. In severe cases, if the above-mentioned staged therapy is ineffective, especially with a large area of skin lesions, the appearance of new blisters and increasing tissue necrosis, plasmapheresis is indicated. A necessary component of the treatment of allergic dermatoses is pain relief and sedation. In these cases, the use of diazepam (seduxen), sodium oxybate, omnopon, promedol, ketamine, which causes dissociated anesthesia, is indicated.

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