Allergic march is a process of sequential development of allergic diseases in children, depending on their age. It includes 3 stages: atopic dermatitis, allergic rhinitis, bronchial asthma. Allergization of the body is caused by food, household, herbal and medicinal antigens. The risk of developing atopy increases in the presence of adverse antenatal factors, exogenous influences. For the diagnosis of allergic march, an immunogram, allergy tests, clinical and biochemical blood analysis are prescribed. Treatment includes elimination measures, pharmacotherapy, specific immunotherapy.
ICD 10
J30.1 J30.3 L20 T78.1
General information
Allergic pathologies occupy one of the leading places in the structure of morbidity worldwide. About 30-40% of the population have at least one manifestation of allergy during their lifetime. Doctors are concerned about the growth of atopy in children, and the first signs often occur before the age of 1 year. Allergic march, which begins in early childhood and accompanies the patient throughout life, requires the development of new methods of early diagnosis and drug control. Today, it is a global problem for all countries, regardless of the level of economic development.
Causes
The etiological factor of the allergic march is the various types of allergens that a person comes into contact with in the first years of life. Most often, the disease starts under the influence of food antigens: cow’s milk, nuts, soy and wheat proteins. The cause of the manifestation of atopy can be household (household dust), epidermal (animal hair and fluff), plant and medicinal allergens. Viruses, bacteria, and fungi are often the trigger.
Of great importance is the predisposition to atopy, which is controlled by genes grouped into 4 classes. They enhance the production of immunoglobulins E, cause a pathological IgE response, activate bronchial hyperreactivity. The genes are located on different chromosomes, so their independent transmission from both parents is possible. In addition to hereditary predisposition, the risk of atopy formation is increased by such factors:
- Physiological features. The age from birth to 2 years of life is the most dangerous in terms of sensitization, which is due to the functional immaturity of all organs and systems. Low activity of local immunity in the intestine and a lack of digestive enzymes cause rapid ingestion of allergens into the body.
- The nature of feeding. The emergence of atopic manifestations in infancy is facilitated by an unreasonably early transition to milk porridges, mixtures based on soy or cow’s milk. There is a particularly high risk of allergy manifestation in the period of 3-6 months of life, therefore, exclusively breastfeeding or adapted milk mixtures are recommended until the age of six months.
- Exogenous effects. Increased allergization of the body is observed when living in an ecologically unfavorable region, exposure to tobacco smoke (passive smoking), unbalanced nutrition and the use of low-quality products. The trigger of atopy is sometimes a sharp change of climate, severe fright, psychoemotional stress.
- Antenatal factors. Pregnancy pathologies (gestosis, abnormalities of placenta attachment, threat of termination) and extragenital diseases of the mother (diabetes mellitus, cardiovascular pathology) have a negative impact on the formation of the child’s immune system. The likelihood of atopy increases with smoking and improper nutrition of a pregnant woman.
Pathogenesis
In modern allergology, there are two hypotheses for the development of allergic march. According to the first, the stages of diseases are associated with improving hygiene and living conditions of the child. Excessive sterility results in reduced microbial exposure at an early age, which shifts the work of the immune system towards the TN2 response. After contact with any allergen, IgE sensitization and allergic inflammation induced by interleukins begin.
The second hypothesis is based on the discovery of a mutation of the filaggrin gene, which causes violations of the skin barrier. In children with such a genetic defect, there is increased dryness of the skin, an overactive TN2 response and excessive production of IgE. The skin becomes a place of constant sensitization to antigens, resulting in the formation of pro-inflammatory factors migrating to the epithelium of the respiratory tract.
Atopy is a narrower concept compared to allergy, which includes only IgE–mediated diseases. Their development is based on an increase in the level of non-specific IgE molecules and specific antibodies to a specific antigen. Children with allergic march have altered reactive sensitivity, so gradually the spectrum of intolerant allergens is expanding, the disease is steadily progressing.
The trigger mechanism of atopic reactions is the interaction of antigens with immunoglobulins E, which are fixed on the surface of mast cells (mastocytes). The largest number of mastocytes is located in the skin, mucous membranes of the respiratory and digestive tract. Histological features determine the high incidence of these “shock” organs and their leading role in the clinical picture.
Symptoms of allergic march
The first “step” and the most striking clinical manifestation is atopic dermatitis, which 45% of children develop before 6 months, mainly associated with food allergens. In infancy, dermatosis is manifested by redness and swelling of the skin, various itchy rashes in the form of nodules and bubbles, wetness and the formation of “serous wells”. The rash is located on the face, extensor surfaces of the extremities, in natural skin folds.
With untimely diagnosis and lack of therapy, the allergic march proceeds to the second stage – the formation of allergic rhinitis. The patient manifests dermatorespiratory syndrome, which is about 30-45% in the structure of childhood allergies. Symptoms begin to develop from the preschool period, the peak of detection falls on the younger and middle school age.
Allergic rhinitis can be permanent or seasonal. It manifests itself with copious liquid secretions, nasal congestion, itching and repeated sneezing. Symptoms develop immediately in response to contact with an allergen. With the long-term existence of the disease, the child suffers from headaches, oxygen starvation of the brain, decreased memory and attention. It is characterized by an “allergic face” with an open mouth, peeling and redness around the nose.
The third stage of the march is bronchial asthma (BA) – one of the most dangerous allergic diseases of children and adults. The combination of atopic dermatitis and AD is observed in 23-25% of patients, with the long-term existence of allergic rhinitis, the risk of developing the disease increases to 45-60%. It is possible to suspect the problem by typical attacks of labored wheezing (sighing), which end with a cough with scant sputum.
Due to the anatomical and physiological features of the respiratory system, bronchial asthma in children often has a severe course and is poorly stopped by standard drug therapy. The triggers of exacerbations are acute respiratory viral infections (in 62% of patients), food allergens and pungent odors (20%), changes in meteorological conditions (16%). Often, the allergic march is accompanied by adenoid vegetations and chronic tonsillitis, which aggravate the course of AD.
Diagnostics
The primary examination of children with signs of allergic march is carried out by a pediatrician about complaints of rashes, frequent acute respiratory infections, difficult nasal breathing. The examination begins with a detailed collection of the anamnesis of the disease, clarification of the peculiarities of pregnancy and childbirth, the presence of allergies in the next of kin. The diagnostic program is selected individually and may include the following methods:
- Hemogram. In a clinical blood test, eosinophilia is determined – a non-specific sign of an active allergic process. Additionally, a study of the level of acute-phase indicators is assigned.
- Immunological tests. To confirm atopy, the total level of IgE, indicators of antibodies to the most common antigens are determined. Diagnosis is of limited value, since the normal value of IgE does not exclude the probability of an allergic march.
- Allergy tests. Tests are performed during the remission period to determine an individual set of triggers and more effective elimination therapy. For this purpose, a prick test, scarification skin tests are carried out.
- Instrumental methods. Taking into account the main clinical manifestations, rhinoscopy and endoscopy of the nose, chest X-ray, bronchoscopy are prescribed. To assess respiratory function in case of suspected bronchial asthma, spirography is performed.
Differential diagnosis
For the differential diagnosis of the symptoms of the allergic march, a pediatric dermatologist, an allergist-immunologist, and a pulmonologist are involved in counseling. The first stage (atopic dermatitis) must be distinguished from seborrhea, diaper dermatitis, immunodeficiency conditions (Wiskott-Aldrich syndrome, hyperimmunoglobulinemia E). Allergic rhinitis requires differentiation with infectious rhinitis, congenital anomalies of the nasopharynx.
Treatment of allergic march
Non-drug methods
Correction of the manifestations of atopy involves a change in lifestyle, the maximum possible elimination of risk factors and protecting the child from contact with potential allergens. Such therapeutic and preventive measures are carried out under the supervision of a pediatrician, and continue throughout the entire period of growing up. Basic principles of observation of patients with atopy:
- mandatory maintenance of a “food diary” by parents;
- long-term retention of breastfeeding (if possible);
- introduction of complementary foods not earlier than 6-7 months of life with restriction of red and yellow products;
- gradual introduction of chicken eggs, fish and cow’s milk into the diet not earlier than 1.5 years of age, nuts – from 3 years;
- creating a hypoallergenic environment at home: daily wet cleaning, reducing the number of fur and textile products, the absence of flowering plants and pets.
Pharmacotherapy
Drug therapy is used to eliminate acute allergies and in the format of supportive treatment for the prevention of exacerbations. When selecting drugs in pediatric practice, their safety for the child’s body, ease of use, and clinical effectiveness are taken into account. The number of medications taken at the same time is limited in order to avoid polypragmasia. The following groups of medications are used to correct the allergic march:
- H1-antihistamines. Selective H1-receptor blockers belong to the first line of treatment of atopic symptoms. They are prescribed in short courses to relieve exacerbations, can be used for a long time (3-6 months) for prevention.
- Stabilizers of mast cell membranes. The drugs have anti-allergic, anti-inflammatory and preventive effects, are well suited for the prevention of bronchoobstructive syndrome. To enhance the effect, they are combined with antileukotriene medications.
- Glucocorticoids. Hormonal agents are prescribed for a short time to relieve severe exacerbations of atopic diseases. In pediatrics, short-acting drugs are used, which are quickly excreted from the body.
In remission, the possibility of allergen-specific immunotherapy is being considered. It involves the introduction of increasing doses of allergens, which leads to a decrease or complete disappearance of symptoms. The method is recommended in cases where it is impossible to exclude contact with an allergen. ASIT provides a prolonged result, prevents the development of cross-allergy, slows down the transition to the next stage of the allergic march.
Prognosis and prevention
The probability of progression of allergic march depends on the completeness of diagnosis and treatment of allergic diseases at an early age. When determining triggers and observing elimination therapy, it is possible to reduce the frequency of clinical exacerbations, achieve regression of symptoms, and prevent the transition of the disease to bronchial asthma. Some children with BA have spontaneous reverse development of symptoms by the age of 16-18.
Effective prevention of allergic march includes a three-stage list of activities that begin before the birth of a child. The task of the first stage is to eliminate toxic effects on the woman and fetus during pregnancy as much as possible. Secondary prevention consists in the elimination of allergens and rational feeding of children. Tertiary prevention involves pharmacotherapy to prevent exacerbations.
