Erythema multiforme is an acute disease of the skin and mucous membranes with polymorphic rashes and a tendency to relapse mainly in the autumn and spring periods. The diagnosis is carried out by excluding diseases similar in clinical picture during the study of smears, fingerprints, syphilis tests, etc. Since erythema multiforme has an allergic mechanism of development, elimination of the etiological factor is important in its treatment.
ICD 10
L51 Erythema multiforme
General information
Erythema multiforme occurs mainly in young people and middle-aged people. It may be associated with sensitization of the body to various medications or develop against the background of some infectious diseases. In the first case, they talk about the toxic-allergic (symptomatic) form of multiform exudative eczema, and in the second – about infectious-allergic (idiopathic). Toxic-allergic variants of erythema multiforme occupy only up to 20% of all cases of the disease, while the bulk of them is associated with exposure to infectious agents.
Causes
Modern dermatology cannot yet unequivocally name the exact causes and mechanism of the development of erythema multiforme. Approximately 70% of patients have a focus of chronic infection (sinusitis, chronic tonsillitis, otitis, pulpitis, periodontal disease, pyelonephritis, etc.) and hypersensitivity to bacterial antigens. In such patients, during the period of exacerbation of the disease, a decrease in T-cell immunity is determined. In this regard, it is assumed that the occurrence or exacerbation of erythema multiforme is due to immunodeficiency, rapidly developing against the background of focal infection when exposed to such provoking factors as hypothermia, acute respiratory infections, angina. In many cases, the association of erythema multiforme with herpetic infection is noted.
The cause of the development of a toxic-allergic form is intolerance to drugs: barbiturates, sulfonamides, tetracycline, amidopyrine, etc. It can also occur after vaccination or serum administration. At the same time, from the point of view of allergology, the disease is a hyperreaction of a mixed type, combining signs of delayed and immediate hypersensitivity.
Symptoms
Infectious and allergic erythema
The infectious-allergic variant has an acute onset in the form of general malaise, headache, fever, muscle pain, arthralgia, sore throat. After 1-2 days, rashes appear against the background of general changes. In about 5% of cases, they are localized only on the oral mucosa. 1/3 of the patients have lesions of the skin and oral mucosa. In rare cases of multiform exudative eczema, there is a lesion of the genital mucosa. After the rash appears, the general symptoms gradually disappear, but may persist for up to 2-3 weeks.
Rashes on the skin with erythema multiforme are located mainly on the back of the feet and hands, on the palms and soles, on the extensor surface of the elbows, forearms, knees and shins, in the genital area. They are represented by flat edematous papules of red-pink color with clear borders. Papules rapidly increase from 2-3 mm to 3 cm in diameter. Their central part sinks, its color acquires a bluish hue. Bubbles with serous or bloody contents may appear on it. The same bubbles appear on seemingly healthy areas of the skin. Polymorphism of rashes is associated with the simultaneous presence of pustules, spots and blisters on the skin. Rashes, as a rule, are accompanied by a burning sensation, sometimes itching is observed.
When the oral mucosa is affected, the elements of erythema multiforme are located in the area of the lips, palate, cheeks. At the beginning, they represent areas of delimited or diffused redness of the mucosa. After 1-2 days, bubbles appear on the areas of erythema multiforme, which open up after 2-3 days and form erosions. Merging with each other, erosions can capture the entire oral mucosa. They are covered with a gray-yellow plaque, the removal of which leads to bleeding.
In some cases of erythema multiforme, mucosal lesion is limited to several elements without pronounced soreness. In others, extensive erosion of the oral cavity does not allow the patient to talk and take even liquid food. In such cases, bloody crusts form on the lips, because of which the patient hardly opens his mouth. Skin rashes resolve on average after 10-14 days, and disappear completely after a month. The process on the mucosa can take 1-1.5 months.
Toxic-allergic erythema
The toxic-allergic form of erythema multiforme usually has no initial common symptoms. Sometimes there is a rise in temperature before rashes. By the nature of the elements of the rash, this form practically does not differ from infectious-allergic erythema. It can be fixed and widespread. In both cases, rashes usually affect the oral mucosa. With a fixed variant, during relapses of erythema multiforme, rashes appear in the same places as before, as well as on new areas of the skin.
The recurrent course of erythema multiforme with exacerbations in the spring and autumn seasons is characteristic. With the toxic-allergic form of the disease, the seasonality of relapses is not so pronounced. In some cases, erythema multiforme has a continuous course due to recurrent relapses.
Diagnostics
To diagnose the disease, a thorough examination of the rash and dermatoscopy is carried out at the consultation of a dermatologist. When collecting anamnesis, attention is paid to the connection with the infectious process or the administration of medications. To confirm the diagnosis of multiform exudative eczema and exclude other diseases, smears-prints are taken from the surface of the affected areas of the skin and mucous membrane.
Erythema multiforme is differentiated with pemphigus, disseminated form of SLE, nodular erythema. The rapid dynamics of the rash, the negative symptom of Nikolsky and the absence of acantholysis in smears-prints make it possible to differentiate erythema multiforme from pemphigus.
With fixed forms of erythema multiforme, it is necessary to carry out differential diagnosis with syphilitic papules. The absence of pale treponemas in the study in a dark field, negative reactions of PCR, IFR make it possible to exclude syphilis.
Treatment
Treatment in the acute period depends on the clinical manifestations. With frequent recurrence, mucosal lesions, disseminated skin rashes, the appearance of necrotic areas in the center of the rash elements, the patient is shown a single injection of betamethasone. With a toxic-allergic form, the primary task of treatment is to determine and remove from the body the substance that provoked the occurrence of erythema multiforme. To do this, the patient is prescribed copious drinking, enterosorbents, diuretics. When a case of the disease occurs for the first time or if there is a history of data on the independent rapid resolution of its relapses, the administration of betamethasone, as a rule, is not required.
Desensitizing therapy is indicated for any form of erythema multiforme: chloropyramine, clemastine, sodium thiosulfate, etc. Antibiotics are used only in case of secondary infection of rashes. Local treatment of erythema multiforme consists in the use of applications of antibiotics with proteolytic enzymes, lubrication of the affected skin areas with antiseptics (e.g. chlorhexidine or furacilin) and corticosteroid ointments, which include antibacterial drugs. When the oral mucosa is affected, rinsing with chamomile decoction, rotokan, and greasing with sea buckthorn oil is prescribed.
Prevention
Prevention of relapses of erythema multiforme in the infectious-allergic form is closely related to the identification and elimination of chronic infectious foci and herpetic infection. To do this, the patient may need to consult an otolaryngologist, dentist, urologist and other specialists. With the toxic-allergic variant of erythema multiforme, it is important not to allow the administration of a disease-provoking medication.
