Diagnosis of bronchial asthma in children

At typical complaints of the patient use the certain algorithm of diagnostics of a bronchial asthma.

[1], [2], [3], [4], [5], [6], [7]

Anamnesis and physical examination

The likelihood of bronchial asthma increases if there is an anamnesis:

• atopic dermatitis;
• allergic rhinoconjunctivitis;
• burdened family history of bronchial asthma or other atopic diseases.

The diagnosis of bronchial asthma can often be assumed if the patient has the following symptoms:

• episodes of dyspnea;
• wheezing; wheezing;
• cough, which intensifies mainly in the night or pre-morning hours;
• congestion in the chest.

The appearance or intensification of symptoms of bronchial asthma:

• after episodes of contact with allergens (in contact with animals, house dust mites, pollen allergens);
• in the night and pre-hours;
• when in contact with the triggers (chemical aerosols, tobacco smoke, acrid smell);
• at changes in ambient temperature;
• for any acute infectious diseases of the respiratory tract;
• with strong emotional stress;
• at physical exertion (patients notice typical symptoms of bronchial asthma or sometimes a prolonged cough that usually occurs 5-10 minutes after the termination of the load, rarely during a load that passes independently for 30-45 minutes).

When examining, it is necessary to pay attention to the following signs, characteristic for bronchial asthma:

• dyspnea;
• emphysematous form of the thorax;
• forced posture;
• distant rales.

With percussion, a boxed percussion sound is possible.

During auscultation, expiratory elongation or wheezing is determined, which may be absent in normal breathing and can be detected only during forced exhalation.

It should be borne in mind that due to the variability of asthma, the manifestations of the disease may be absent, which does not exclude bronchial asthma. In children under 5 years of age, the diagnosis of bronchial asthma is based mainly on the history and results of a clinical (but not functional) examination (most pediatric clinics do not have such accurate equipment). In infants who had three episodes of wheezing and more associated with the action of triggers, with atopic dermatitis and / or allergic rhinitis, eosinophilia in the blood should be suspected bronchial asthma, to conduct examination and differential diagnosis.

[8], [9], [10], [11]

Laboratory and instrumental diagnostics of bronchial asthma

Spirometry

In children older than 5 years, it is necessary to assess the function of external respiration. Spirometry allows assessing the degree of obstruction, its reversibility and variability, as well as the severity of the course of the disease. However, spirometry allows you to assess the child's condition only at the time of the examination. When assessing the indicators of FEV ₁ and forced vital capacity of the lungs (FZHOL), it is important to focus on the proper indicators obtained in the course of population studies that take into account ethnic characteristics, gender, age, and growth.

Thus, the following indicators are evaluated:

• FEV;
• FVC;
• ratio of FEV, / FZHOL;
• reversibility of bronchial obstruction - an increase in FEV, at least 12% (or 200 ml) after inhalation of salbutamol, or in response to trial treatment with glucocorticosteroids.

Peakflowmetry

Peakflowmetry (definition of PSV) is an important method of diagnosis and subsequent monitoring of bronchial asthma treatment. The latest models of peak flowmeters are relatively inexpensive, portable, made of plastic and are ideal for use by patients over 5 years at home with the goal of daily assessment of the course of bronchial asthma. When analyzing PSV indicators, children use special nomograms, but daily monitoring of PSV for 2-3 weeks is more informative for determining the individual best score. PSV is measured in the morning (usually the lowest rate) before inhalation of bronchodilators, if the child receives them, and in the evening before bedtime (usually the highest rate). Filling patients with self-monitoring diaries with daily registration of symptoms, PSV results plays an important role in the strategy of treating bronchial asthma. Monitoring PSV can be informative for determining early symptoms of exacerbation of the disease. The daily spread of PSV indices more than 20% is considered as a diagnostic sign of bronchial asthma, and the magnitude of deviations is directly proportional to the severity of the disease. The results of peakflowmetry indicate a diagnosis of bronchial asthma, if PSV increases by at least 15% after inhalation of the bronchodilator or in the trial designation of glucocorticosteroids.

Thus, it is important to evaluate:

• daily variability of PSV (the difference between the maximum and minimum values during the day, expressed as a percentage of the average for day PSV and averaged over 1-2 weeks);
• the minimum PSV value for 1 week (measured in the morning before taking the bronchodilator) as a percentage of the best indicator in the same period (Min / Max).

Detection of airway hyperreactivity

In patients with symptoms characteristic of bronchial asthma, but with normal lung function, the study of the response of the respiratory tract to physical exercise may help in the diagnosis of asthma.

In some children, the symptoms of bronchial asthma are provoked only by physical activity. In this group, it is useful to carry out a load test (6-minute run-time protocol). The use of this research method in conjunction with the definition of FEV, or PSV, can be useful for establishing an accurate diagnosis of bronchial asthma.

To detect bronchial hyperreactivity, a test with methacholine or histamine can be used. In pediatrics they are appointed extremely rarely (mostly in adolescents), with great care, for special indications. When diagnosing bronchial asthma, these tests have high sensitivity, but low specificity.

Specific allergological diagnosis is carried out by allergy doctors / immunologists in specialized institutions (departments / offices).

Allergological examination is mandatory for all patients with bronchial asthma, it includes: collection of allergological anamnesis, carrying out skin testing. Determination of the level of total IgE (and specific IgE in cases where it is impossible to carry out skin tests).

Skin tests with allergens and determination of the levels of specific IgE in the blood serum help to identify the allergic nature of the disease, establish causal allergens, on the basis of which recommend appropriate control of environmental factors (elimination regime) and develop specific immunotherapy regimens.

Noninvasive detection of markers of inflammation of the respiratory tract (additional diagnostic methods):

• sputum examination, spontaneously produced or induced by inhalation of hypertonic sodium chloride solution, on inflammatory cells (eosinophils or neutrophils);
• determination of the level of nitric oxide (NO) and carbon monoxide (FeCO) in the exhaled air.

[12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22]

Determination of the severity of exacerbations of bronchial asthma and indications for hospitalization during exacerbation

Determination of the severity of exacerbations of bronchial asthma

Index	An easy exacerbation	Severe-severe exacerbation	Severe exacerbation	Stopping breathing is inevitable
Dyspnea	When walking; can lie	When talking; crying is quieter and shorter, difficulty in feeding; prefers to sit	At rest; stops eating; sits, leaning forward
Speech	Suggestions	Individual phrases	Individual words
Level of wakefulness	Can be excited	Usually excited	Usually excited	Braked or in a confused state
BHP	Increased	Increased	High (> 30 per minute)	Paradoxal breathing
Whistling wheezing	Moderate	Loud	Usually loud	None
Heart rate	<100 / min	100-120 per minute	> 120 per minute	Bradycardia
PSV	> 80%	60-80%	<60%
PaCO2	There is usually no need to measure	> 60 mm Hg. Art.	<60 mm Hg. Art.
PaCO2	<45 mm Hg. Art.	<45 mm Hg. Art.	> 45 mmHg.
SaO2	> 95%	91-95%	<90%
Paradocepotic pulse	Absent, <10 mm Hg. Art.	It is possible, 10-25 mm Hg. Art.	Often, 20-40 mm Hg. Art.	Absence indicates fatigue of the respiratory muscles
Involvement of accessory muscles in the act of breathing, retraction of the supraclavicular pits	Usually not	Usually there is	Usually there is	Paradox-sebaceous movements of the chest and abdominal wall

Normal respiratory rate in children:

• more than 2 months - <60 per minute;
• 2-12 months - <50 per minute;
• 1-5 years - <40 per minute;
• 6-8 years - <30 per minute.

Normal pulse in children:

• 2-12 months - <160 per minute;
• 1-2 years - <120 per minute:
• 2-8 years - <110 per minute.

[23], [24], [25], [26], [27], [28],

Differential diagnosis of bronchial asthma

[29], [30], [31], [32], [33], [34], [35], [36], [37],

Young children

Diagnosis of bronchial asthma in young children is difficult due to age restrictions on the use of a complex of diagnostic measures. It is based primarily on clinical signs, symptom assessment and physical examination data.

Differentiate the three variants of wheezing in the anamnesis in young children:

• Transient early wheezing occurs in the first 3 years of life and is associated with prematurity of children and smoking of parents (although there are studies showing that bronchopulmonary dysplasia of premature infants is a predictor of asthma in children Eliezer Seguerra et al., 2006).
• Persistent rales with an early onset are associated with ARVI (at the age of 2 years - a respiratory syncytial virus infection) in the absence of signs of atopy in children.
• Chryps with late onset of bronchial asthma are present throughout childhood and continue in adulthood with atopy in a history of patients.

Clinical criteria for differential diagnosis of bronchial asthma and symptoms of obstruction in the context of acute respiratory infection in young children

Symptoms	Bronchial asthma	Symptoms of obstruction in ARI
Age	Older than 1,5 years	Younger than 1 year
The appearance of bronchial obstructive syndrome	Upon contact with the allergen and / or in the first day of ARI	Absence of relationship with contact with allergens, the onset of symptoms on the 3rd day of ARI and later
Duration of episodes of bronchial obstructive syndrome with ARI	1-2 days	3-4 days or more
Repetition of bronchial obstruction syndrome	2 times or more	First
Hereditary weighed down by allergic diseases	There is	No
Including maternal bronchial asthma	There is	No
Immediate allergic reactions to food, medicine, preventive vaccinations in history	There is	No
Excess household antigenic load, the presence of dampness, mold in a dwelling	There is	No

With repeated episodes of wheezing, the following diseases should be excluded:

• aspiration of a foreign body;
• cystic fibrosis;
• bronchopulmonary dysplasia;
• developmental defects, which cause narrowing of the intrathoracic airways;
• syndrome of primary ciliary dyskinesia;
• Congenital heart defect;
• gastroesophageal reflux;
• chronic rhinosinusitis;
• tuberculosis;
• immunodeficiencies.

Older children

Older patients need differential diagnosis of bronchial asthma with the following diseases:

• obstruction of the upper respiratory tract (respiratory papillomatosis);
• Aspiration of foreign bodies;
• tuberculosis;
• hyperventilation syndrome and panic attacks;
• other obstructive pulmonary diseases;
• dysfunction of the vocal cords;
• non-obstructive pulmonary diseases (for example, diffuse lesions of the lung parenchyma);
• severe chest deformity with compression of the bronchi;
• congestive heart defects;
• tracheo-or bronchomalacia.

With the following symptoms, it is necessary to suspect a disease different from bronchial asthma.

• History data:
  • neurological dysfunction in the neonatal period;
  • absence of effect from the use of bronchodilators;
  • wheezing associated with feeding or vomiting;
  • difficulty swallowing and / or recurrent vomiting;
  • diarrhea;
  • bad weight gain;
  • preservation of the need for oxygen therapy more than 1 week after the exacerbation of the disease.
• Physical data:
  • deformation of fingers in the form of "drumsticks";
  • noises in the heart;
  • stridor:
  • focal changes in the lungs:
  • crepitus at auscultation:
  • cyanosis.
• Laboratory and instrumental research results:
  • focal or infiltrative changes on the chest X-ray:
  • anemia:
  • irreversible airway obstruction;
  • hypoxemia.