Pollinosis in children
Last reviewed: 23.04.2024
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Pollinosis in children is largely genetically determined by the key pathogenesis - increased IgE synthesis.
It has been shown that the ability for increased production of IgE is inherited by a recessive-dominant type and is necessary, but not the only condition for the formation of allergies to pollen of plants. Positive associations of diseases with pollinosis with HLA B-7, B-8, B-12 were revealed. In most patients with pollinosis, children are preceded by early skin allergy symptoms, food allergies and early production of reactants (IgE) in elevated amounts.
In the pathogenesis of pollinosis in children, the role of deficiency of secretory IgA, violation of the barrier functions of the upper respiratory tract, violation of the local protective function of macrophages and granulocytes, decrease in the production of a substance inhibiting the activity of the pollen permeability factor.
In the etiology of pollinosis in children, according to the researchers, the leading role is played by pollen of cereal grasses, the sensitivity to which is found in 75% of the examined, somewhat less frequently, but often enough - pollen of trees (in 56% of patients) and in 27% of children is sensitized to pollen of weeds (wormwood, quinoa). In 64% of children with pollinosis, the disease develops as a result of polyvalent allergies.
Allergens of pollen of plants refer to aeroallergens. Of the many thousands of plants on Earth, only about 50 produce pollen responsible for the occurrence of pollinosis. Male genital elements in mainly wind-polluted plants cause sensitization. The grains of these pollen species have a rounded shape and a diameter of not more than 35 μm. Sensitization in each geographical area occurs to the pollen of widespread plants that produce a huge amount of pollen (one ragweed bush allocates up to 1 million pollen grains per day).
There are three main groups of allergenic plants:
- wood;
- cereals;
- motley grass (weeds).
The first spring peak of high frequency of pollen allergy (April-May) causes pollen of trees: hazel, alder, oak, birch, ash, nut, poplar, maple, etc. The role of pollen of pine and spruce in the occurrence of allergic diseases of the respiratory tract is low.
The second summer rise in pollen concentration (June-August) is associated with the flowering of grasses: bluegrass, grasshopper, fire, fescue, hedgehog, foxtail, rye, maize, etc. The flowering season of these herbs coincides with the high concentration of poplar fluff in the air, which is often mistaken for patients for reaction to fluff.
The third autumn peak of pollen allergy (August-October) is caused by plants with the greatest allergenic activity. These include weeds: ambrosia, quinoa, dandelion, hemp, nettle, wormwood, buttercup, etc.
What causes the hay fever in children?
Symptoms of hay fever begin with rhinoconjunctival symptoms. The onset of the disease coincides with the dusting of plants that are allergens to the baby, allergy symptoms are usually repeated at the same time each year. There is itching and burning eyes, at the same time with itching or before it, there are lacrimation, puffiness of the eyelids, hyperemia sclera. Itching can be in the nose area, there is scratching of the nose (so-called "allergic salute"). Characteristic sneezing, abundant watery discharge from the nose, difficulty in nasal breathing. Clinical manifestations persist throughout the flowering period of plants that are allergens. In winter and autumn, patients do not complain. A significant difference between pollen conjunctivitis and other inflammatory diseases of the mucous membrane of the eyelids is the scarcity of the discharge.
The diagnosis of pollinosis is established on the basis of typical clinical manifestations of the disease in spring and summer. Rinoscopically determine the pale or bluish color of the nasal mucosa, an increase in the inferior nasal shell. The presence of clinical and anamnestic signs of pollinosis is the basis for an allergological examination (conducted outside the flowering season). Since, regardless of the site of the synthesis, allergen-specific IgE antibodies are evenly distributed in the skin, nasal mucosa and serum of patients, endo-initial or conjunctival provocative tests (according to indications), prik test and skin scarification tests, the determination of specific IgE are carried out. During the exacerbation, a large number of eosinophils can be detected in nasal secretions, persistent eosinophilia of peripheral blood (12% or more).
In order to effectively treat pollinosis, along with rational pathogenetic therapy, an important role is played by the regime of the maximum possible limitation of the level of antigen stimulation. During the remission period, the main and most effective method of treating patients with pollinosis is specific hypo-sensitization.
Elimination of pollen is impossible.
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