20.10.2020

Causes of Allergic Cough in a child

Allergic cough in children is one of the symptoms of allergies that occurs on the background of inflammation and swelling of the tissues of the bronchi, trachea, larynx. Has an unproductive, paroxysmal character. Formed in both acute and chronic inflammatory reactions. Accompanying diseases such as allergic laryngitis , tracheitis , bronchitis, bronchial asthma and others. 

Currently, there is an increase in the frequency of allergic pathologies among children around the world. About 10-12% of the pediatric population suffers from any type of atopy, the primary detection of the disease occurs between the ages of 5 and 12 years. Children under three years of age practically do not suffer from the above pathologies.

Causes of Allergic Cough in Children

Etiological factors provoking a cough attack are non-microbial antigens that enter the body along with inhaled air from the outside, or infectious pathogens that parasitize the body. Moreover, for the development of an allergic reaction, conditions such as the antigenic load on the body and the state of the immune system in a child are most important.

The most significant causes can be divided into three groups:

  • Inhalation of allergens and pollutants . The leading etiopathogenetic factor of allergic cough is the entry of antigens into the respiratory tract during respiration. Allergens are particles of house dust, wool or feathers of domestic animals, plant pollen, aerosol chemicals. Thus, respiratory allergies are formed: pharyngitis , laryngitis, pollinosis , bronchitis, bronchial asthma .
  • Fungal lesions of the respiratory tract . Penetration of yeast and mold fungi (aspergillus, candida, penicilla, cladosporium , alternaria) or their dispute into the lumen of the larynx, bronchi leads to the occurrence of infectious and / or allergic inflammation. The development of deep mycoses (fungal pharyngitis, laryngitis) is promoted by imperfect immunity in young children, unfavorable living conditions: the appearance of mold on the walls, dampness.
  • Parasitic invasions . With helminthiases ( ascariasis , toxoplasmosis, toxocarosis ) and protozoal infections ( amebiasis , giardiasis ), cough does not occur as a result of direct exposure of antigens to the respiratory tract, but due to the general allergization of the body (increased IgE, eosinophilia, release of inflammatory mediators). Against this background, children with atopy often exacerbate other allergic manifestations, including respiratory: persistent cough paroxysms, bronchospastic reactions occur.

The course of cough syndrome is influenced by non-specific trigger factors, which themselves do not cause an allergic reaction, but contribute to its formation. These are the uncoordinated work of the immune system in childhood, heredity, passive or active (independent) smoking, chronic bacterial inflammation of the respiratory system.

Pathogenesis

The development of allergic cough genesis is largely due to the reagine (IgE-mediated) type of tissue damage, in which basophils, mast cells, eosinophils are involved. This type of allergic reaction is called immediate type hypersensitivity. Pathogenesis can be divided into three phases. In the immunological phase, the allergen interacts with macrophages and B-lymphocytes are attracted, which subsequently produce IgE antibodies. The latter, in turn, circulating in the general bloodstream, settle on the mast cells and are in an inactive state.

The pathochemical phase begins when the allergen is reintroduced into the body. At the same time, mast cells are degranulated, that is, mediators of first-order inflammation (histamine, tryptase) and second order (leukotrienes, prostaglandins) are released into the blood. In the pathophysiological phase, the contractility of bronchial smooth muscle tissue increases, mucus overproduction, infiltration and damage to the mucous membrane are observed. Against the background of irritation and active inflammation, a reflex response appears in the form of a cough.

Symptoms of allergic cough in children

Allergy cough is usually unproductive, paroxysmal, barking, rough, does not go away for several weeks or months. Sometimes sputum is released – clear, inviscid, without admixture of pus or blood. There are no signs of intoxication, body temperature does not rise, does not bother chills. Cough may be the only manifestation of allergies or is combined with symptoms such as runny nose, sneezing, itching mucous membranes. With a prolonged long-term cough, pain in the chest area due to overstretching of the skeletal muscles is possible, at rest they pass on their own. When allergic conjunctivitis is attached, the clinic is supplemented with redness, swelling of eye tissues, and tearing.

The nature of allergic cough depends on the type of underlying disease. In case of bronchial asthma, it develops against the background of bronchospasm, is accompanied by difficulty in exhalation, worries mainly at night or when the child wakes up. A cough attack may occur during exercise, laughter, crying or exposure to tobacco smoke. At the time of the attack, the patient breathes through his mouth and tries to take a sitting position with his hands resting on the table or chair seat, because breathing is facilitated by the use of additional skeletal muscles. At the end of a cough paroxysm, a small amount of transparent mucous sputum may be separated.

In allergic laryngitis, the cough is dry, barking, combined with sore throat and hoarseness. If the disease progresses, the clinical picture is complemented by shortness of breath, painful swallowing or a feeling of an obstructive lump in the throat, cyanosis of the lips and nasolabial triangle, weakness due to tissue hypoxia. In chronic allergic alveolitis , a cough appears with the release of a small amount of mucous sputum, it occurs regardless of the time of day. On the background of a cough attack, you may experience headache, increase blood pressure or heart rate.

Obstructive bronchitis with unproductive cough, wheezing and intermittent shortness of breath is characteristic of toxocariasis and giardiasis . Due to the sensitization of the body, a rash, redness, itching of the skin. Against the background of ascariasis, in the absence of treatment, the formation of eosinophilic pneumonia is possible , in which case the cough is supplemented by fever, weakness, and malaise.

Complications

Allergic diseases caused by hypersensitivity and accompanied by cough attacks, without proper treatment can result in serious complications: the transition of acute inflammation in a chronic form, followed by the formation of foci of fibrosis , the formation of pulmonary heart on the background of stagnation of blood in the pulmonary circulation and the development of respiratory failure , stenosis of laryngitis, asthma status . With the last three pathologies required urgent hospitalization of the child in the intensive care unit.

Diagnostics

In the course of diagnosis, the collection of complaints, clarification of the history of the disease, the nature of cough, and the seasonality of the onset of symptoms are of great importance. The doctor (pediatrician, pediatric allergist, pediatric pulmonologist) should know for sure the duration of the course of allergy, the treatment regimen and its duration depend on it.

The survey consists of the following steps:

  • Primary consultation. A child is examined, percussion and auscultation of the lungs. In asthma or allergic alveolitis, dry wheezing is heard, aggravated during exhalation. Crepitus is possible in the lower parts of the lungs. Palpation of the chest pain is not observed.
  • Laboratory diagnosis. In general, the analysis of blood increases the number of neutrophils, eosinophils, the erythrocyte sedimentation rate increases. An immunological study of blood serum determines high concentrations of IgE, sometimes – IgM and IgG. In asthma sputum, eosinophils, Charcot-Leiden crystals, Kursman spirals appear. In the case of a supposed parasitic invasion, a fecal analysis for helminths and protozoa is assigned within the search for the cause.
  • Instrumental diagnostics . In spirometry, a decrease in the forced expiratory volume in one second (FEV1) and a decrease in the forced vital capacity of the lungs (FVC) are recorded. On a review radiography or computed tomography of OGK with a prolonged attack of cough and severe allergy, there is an increase in pulmonary pattern, expansion of the vessels of the roots of the lungs.
  • Allergy tests . If the skin tests are performed correctly, the presence of hyperreactivity in response to the use of certain allergens can be detected. Allergy tests are appointed from 2 years. Until this age, it is possible to perform skin tests, but their information content is significantly reduced, there is a probability of false positive results.

Differential diagnosis should be carried out with other types of cough occurring in acute respiratory viral infections , acute bacterial bronchitis, pneumonia , laryngitis, tracheitis. Barking, convulsive cough – the main symptom of whooping cough , tuberculosis . A cough in combination with frequent breathing and an abrupt development of cyanosis indicates that a foreign body has entered the trachea or bronchi.

Treatment of allergic cough in children

Treatment, as well as prevention, of any allergic disease begins with the elimination of contact with the allergen, otherwise any etiotropic therapy will be ineffective. The treatment regimen is determined based on the course of the disease and the characteristics of the child’s body.

The following treatment options are most commonly used:

  • Antiallergic therapy. Antihistamines block histamine receptors and thereby eliminate the inflammatory response caused by the same-name mediator. Preparations of the second and third generation have a longer duration of action and almost do not cause drowsiness.
  • Inhalation therapy with glucocorticosteroids . GCS in a short time eliminate inflammation, mucus production, relieve tissue swelling and increase the bronchial lumen. Used for the treatment of bronchial asthma, relief of cough attack. The dosage is selected taking into account the age, frequency of exacerbations of allergic diseases.
  • Expectorants. They have a symptomatic effect, since they do not act on etiopathogenesis, but reduce the severity and duration of cough. Thinning mucus and enhancing its elimination improves the airway.
  • ASIT . Allergy-specific immunotherapy (ASIT) is considered a specific area of ​​treatment for allergic diseases. It includes oral or injectable administration of small doses of allergens with a gradual increase in the concentration of the active ingredient. In pediatrics and allergology, in this way, the formation of the body’s resistance to the antigen and the elimination of respiratory allergies are achieved. ASIT begin to hold with five years.

If a parasitic invasion is detected, consultation of a pediatric infectious disease specialist is required, after which anti-parasitic agents are prescribed. Preference is given to universal drugs that destroy a large range of pathogens, thus, it is possible to avoid a combination of several drugs and reduce the risk of side effects.

Prognosis and prevention

If the recommendations of the pediatric allergist are met and the source of allergization is eliminated, the prognosis is favorable, the risk of negative consequences is minimal. Prevention of allergic cough is to create around the child a hypoallergenic environment, timely treatment of associated diseases, improving living conditions. It is undesirable to keep books on the open shelves and cover the floors with carpets, as these are the main sources of household dust. It is necessary to minimize the number of plush, textile toys from children, to buy plastic or rubber products that do not emit chemical odors.

Allergic cough in children is a protective reaction of the body to the ingress of antigens into the respiratory tract, followed by the formation of hypersensitivity and the development of a specific clinical picture. Allergic cough is paroxysmal, may be dry or with a small amount of clear sputum, sometimes accompanied by bronchospasm and other signs of allergies (sneezing, runny nose, watery eyes). Diagnosis requires consulting a pediatric allergist or pulmonologist, spirometry, allergy testing. Treatment involves the elimination of contact with antigens, the use of antihistamines, anti-inflammatory drugs, ASIT.

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