Erythema toxicum is a local change in the color of the skin and mucous membranes of an inflammatory nature against the background of general intoxication of the body. Clinically, the pathological process is characterized by polymorphic rashes, since erythema toxicum with the passage of time and the aggravation of sensitization of the body is able to transform into nodules and pustules that open with the formation of crusts. Primary elements tend to spread and form foci with fuzzy boundaries. The diagnosis is made by a dermatologist on the basis of anamnesis, clinic, allergic tests, microscopy of skin scrapings, examination of breast milk. Treatment consists in eliminating the cause and using antihistamines.
Erythema toxicum is a borderline condition between health and a pathological process, has an allergic nature, is characterized by a rash of hyperemic hot spots on the skin. Some experts believe that the appearance of cases of erythema toxicum in newborns is a harbinger of complications of the epidemiological situation. According to various authors, the disease occurs in 4-70% of newborns, the statistics of the prevalence of the process in adults is unknown. If pathology occurs in newborns, only full-term infants who are breastfed fall into the risk group.
Erythema toxicum does not have seasonality, occurs in any geographical latitudes, has no racial differences, occurs equally often in both women and men. The urgency of the problem is associated with the ability of local erythema to transform into generalized forms that pose a danger to human life, requiring hospitalization, as well as with the fact that the pathological process is a kind of marker of the epidemiological situation in a medical institution, region, country.
The triggers of the pathological process are both exogenous (ecology, contact with low-quality perfumes, plants) and endogenous (hereditary predisposition, medications, food) factors. In newborns, the risk of developing pathology increases many times if the mother’s pregnancy proceeded with complications (fetal hypoxia), in an environmentally unfavorable area, and also if more than 6-12 hours have passed between the birth of the baby and its first application to the breast.
The mechanism of development of erythema toxicum is associated with the expansion of the capillaries of the skin in response to the introduction of a pathogenic allergen. Initially, as a compensatory reaction, the immune and reticular systems of the dermis are activated in the body, T-lymphocytes begin to actively produce antibodies designed to bind and neutralize antigens foreign to the body. An allergic reaction in the skin causes irritation of the receptors, the receptors transmit a signal to the capillaries, the capillaries expand, a hot hyperemic spot forms on the surface of the dermis.
Over time, the allergen intake becomes so large-scale that autoimmune defense mechanisms are activated, causing damage to the cells of the surface layer of the skin. Cytokines, prostaglandins, inflammatory mediators are released into the dermis, stimulating the onset of the inflammatory process and the proliferation of epidermal cells. Nodules, papules, vesicles with serous contents appear on the skin, opening and forming crusts, so polymorphism of rashes with erythema toxicum is formed. Since normal capillary blood circulation in the dermis is designed to provide every skin cell with nutrients and remove decay products, with the onset of the pathological process, the vessels additionally expand to remove harmful substances, therefore erythema toxicum persists until the regression of the primary elements.
In modern dermatology, there are several classifications of the pathological process, all of them are of practical importance, they help to determine the tactics of managing patients (children and adults). There is congenital (develops in utero) and acquired (occurs during life under the influence of exogenous and endogenous factors) erythema toxicum. In addition, localized and generalized forms of the pathological process are distinguished. In newborns, physiological and pathological erythema toxicum are distinguished.
Physiological erythema toxicum is called skin catarrh or transient erythema of newborns. In fact, this is an allergic reaction of unclear etiology that occurs spontaneously on the 2-5 day of the baby’s life, manifested by polymorphic flaky rashes over the entire surface of the skin, excluding palms and soles, and disappears after 3 days. Probably, this is a reaction of the newborn associated with the disappearance of the protective intrauterine film. Pathological erythema toxicum is associated with the development of allergies as a result of the complete loss of the newborn’s original lubricant, considering it as an adaptive reaction to the environment.
Erythema toxicum is also divided into stages. At the first, pathochemical stage, a typical physiological allergic reaction develops, an allergen-antibody in response to the body’s contact with a foreign origin. This stage is the forerunner of the further development of allergy in the patient. The second stage is called pathophysiological, characterized by a violation of immune processes in the body, their transformation into autoimmune with damage to the skin and mucous membranes as a result of infection, severe hypothermia, disorders in the digestive system. There is a division of erythema toxicum by the nature of clinical manifestations into spotted (the lightest), bullous (vesicles are formed with the outcome in crusts) and nodular (foci of erythematous nodes with indistinct outlines are formed) varieties.
The pathological process develops either spontaneously or 1-3 days after direct contact with the allergen. On unchanged skin or mucous membranes, slightly itchy, hot to the touch erythemas are formed. Primary rashes are localized most often in places typical for the manifestation of allergies: on the face, abdomen, forearms, thighs, buttocks, but never on the palms and soles. The primary elements of erythema toxicum tend to spread. Over time, not only areas of hyperemia appear on the skin, but also bullous elements, nodules that form “blurred” foci of skin inflammation.
It is possible to attach a secondary infection. Polymorphic rash may be accompanied by prodromal phenomena, an increase in lymph nodes. With the generalization of erythema toxicum, the subjective state of the patient is significantly disturbed, hospitalization in a hospital is required. It is worth noting that the generalization of the process is usually observed in newborn boys and is practically not detected in other groups of patients. The severe variant of erythema toxicum is characterized by frequent relapses occurring at two-week intervals. Usually the rash disappears within two to four days.
Dermatologists, allergologists, pediatricians are engaged in the diagnosis of the pathological process. The diagnosis of erythema toxicum is made on the basis of anamnesis and clinical manifestations with mandatory general laboratory tests (blood test, urine test, feces for worm eggs), microscopy of the upper layer of the epidermis, allergic tests, examination of the composition of mother’s milk. Allergic tests are designed to identify the provoking factor, are divided into skin and provocative.
Skin allergic tests for erythema toxicum are carried out in the form of scarifications (various allergens are drip-applied to the forearm and the skin is scratched through them), prick tests (needle injections are used instead of a scarifier), application tests (the skin comes into contact with cotton swabs soaked in allergen) and subcutaneous (allergens are injected) tests. No more than 15 allergens are used at a time. Provocative tests are carried out when there is a discrepancy between the clinical symptoms of erythema toxicum and the results of skin tests. The essence of the method is to apply the allergen to the mucous membranes. In addition, with erythema toxicum, blood testing is used for the presence of specific antigens. The allergist evaluates the results of the tests.
The primary task of the therapy of the pathological process that has arisen is to exclude contact with the allergen that caused the allergic reaction. During the treatment of erythema toxicum, detoxification is also carried out, diuretics, vitamin therapy and antihistamines are prescribed. Externally, chatterboxes with zinc, aniline paints and oil solutions with vitamins are used. In addition, with erythema toxicum, a diet with an increased content of vitamins and minerals is recommended. Prevention comes down to hardening. The prognosis is usually favorable, self-resolution of the process is possible.