Definition
Bronchiolitis means an acute inflammatory process, characterized by the obstruction of the bronchioles (the last bronchial branches): typical early childhood disease, bronchiolitis causes respiratory difficulty, serous nasal discharge, sneezing and loss of appetite.
Incidence
The target of bronchiolitis is represented by early childhood, in particular by children under the age of 2 years: infants, until they reach six months, are by far the most endangered category.
The degree of severity of the disease is inversely proportional to the age of the child: in other words, a child of a few months affected by bronchiolitis tends to present a much more severe symptomatology than an older child.
Medical statistics show that, at the same age, males are more at risk of bronchiolitis than females. Although bronchiolitis cannot properly be defined as a seasonal disease, in the winter period there are generally more affected children.
Globally, 150 million new cases of bronchiolitis are reported each year, almost all of which (95%) are observed in developing countries.
Bronchiolitis and colds
In the previous section we have investigated bronchiolitis in children: this does not mean, however, that this disease can also affect the adult. In fact, bronchiolitis does not only affect infants: often, however, bronchiolitis in adults is mistakenly diagnosed as a simple cold or, in other cases, is asymptomatic or in any case not very problematic.
Contagion
Bronchiolitis is an infection that is transmitted by air, through saliva / nasal secretions of infected patients, or by means of micro-droplets of saliva that are dispersed in the environment following sneezing or coughing. After infection, it is estimated that the incubation time of the micro-organism is around 4 days: infected children can transmit bronchiolitis even after a week / 10 days from infection.
Causes
The main etiopathological element responsible for bronchiolitis is a virus: in particular, it is the Respiratory Syncytial Virus (Respiratory Syncytial Virus, or RSV).
VRS is highly resistant to common antiseptic substances (disinfectants), as well as to classic environmental sterilization techniques.
However, other possible microorganisms directly or indirectly related to the manifestation of bronchiolitis have been isolated:
- Type B influenza virus
- Parainfluenza viruses of types 1, 2 and 3
- Adenovirus type 1, 2 and 5: in this case, the bronchiolitis is more precisely defined obliterating, since it destroys the small bronchial branches
- rhinovirus
- Mycoplasma pneumoniae : microorganism responsible for a particular form of bronchiolitis that affects children of school age.
- Chlamydia: unlike the microorganisms listed above, chlamydia is a bacterium: it is responsible for a type of particularly ferocious bronchiolitis, especially for newborns and infants up to 3 months.
Risk factors
Despite the Respiratory Syncytial Virus being the main causal element, bronchiolitis is also correlated to further risk factors, which affect more or less severely depending on the sensitivity of the subject and the age of onset of the disease.
Among the most alarming risk factors, the supremacy is certainly due to cigarette smoking: it has been shown that children born to smoking mothers are more exposed to bronchiolitis in the first months of life, since their lung parenchyma is strongly altered - especially in terms of elasticity - following an intrauterine exposure to cigarette smoke.
Clearly, even crowded places are possible risk factors, as the chances of contagion increase considerably. Still, lung diseases, heart disease, prematurity of birth and artificial breastfeeding are additional factors that increase the risk of contracting bronchiolitis.
