Bronchial asthma is a common chronic condition that makes a significant contribution to the overall incidence of children. According to the US National Center for Medical Statistics 1998, a diagnosis of bronchial asthma was made in 8.65 million (12.1%) children, and 3.8 million (5.3%) had asthma attacks during the previous year .
In the United States, bronchial asthma is the most common cause of emergency care (867,000 visits per year), hospitalization (166,000 cases per year), and missed school (10.1 million days per year). Although this disease in children is relatively rare leading to death (0.3 cases per 100,000 population per year), in 1998, 164 children died from it in the United States. Timely diagnosis and proper treatment could obviously prevent many of these cases.
The number of hospitalizations and deaths among African-American children is more than 3 times higher than the corresponding rates among white children. The high likelihood of severe asthma attacks among an ethnic minority living in urban ghettos in the USA is associated with the complex effects of biological, environmental, economic and psychosocial factors.
Although the prevalence of bronchial asthma among the black population of our country, according to 1998 data, is slightly higher (16.1%) than among whites (13.2%), this indicator seems to be little dependent on ethnicity or income families. Thus, if mortality from asthma is associated with these factors, then the prevalence of this pathology itself is determined mainly by urban living conditions.
Despite the emergence of new drugs and a significant improvement in the treatment of bronchial asthma, the frequency of this disease among children is increasing everywhere. In the United States, for example, from 1982 to 1994, the incidence of asthma in children increased by 72%. According to numerous studies in other countries, the incidence of asthma is increasing by 50% every 10 years. However, the prevalence of bronchial asthma among children in different regions is far from uniform.
According to a large international study of asthma and allergic diseases in children, covering 56 countries, the prevalence of bronchial asthma in different countries varies about 20 times (1.6-36.8%). In addition, a correlation was found between this indicator and the frequency of allergic rhinoconjunctivitis and atopic eczema (correlation coefficients 0.75 and 0.74, respectively). Bronchial asthma and other allergic diseases are especially often detected in children living in large modern cities.
Among children living in rural areas of developing countries (African countries, China, India), as well as in agricultural areas of Germany, Austria, Switzerland, Finland and Quebec, all these diseases are much less common. Such large differences prompted the study of the role of environmental factors and lifestyle in the development of these diseases.
In approximately 80% of patients, bronchial asthma occurs before the age of 6 years. However, at an older age, this disease persists only in some of those who previously suffered from repeated attacks of suffocation. The main among them is an allergy, which in early childhood can manifest itself with symptoms of diffuse neurodermatitis, allergic rhinitis, or food allergies.
There are two main types of childhood bronchial asthma : 1) repeated attacks of suffocation in early childhood, mainly associated with common viral infections of the respiratory tract, and 2) allergy-related chronic bronchial asthma, which persists in late childhood, and often in adulthood. A third type of childhood bronchial asthma is characteristic of girls with obesity and early onset of sexual development (by 11 years of age).
The fourth species (which is often not isolated) is observed in children living surrounded by farm animals. An asthmatic triad characterized by a combination of bronchial asthma, recurring nasal polyposis and intolerance to aspirin and non-steroidal anti-inflammatory drugs – NSAIDs (e.g., ibuprofen), is rarely observed in childhood. Among these various types of childhood asthma, the most common is that which is caused by allergies. In addition, sensitization to allergens and their effects lead to a more severe course of asthma.