Bronchiolitis is a "viral infection that occurs suddenly (acute) and affects the bronchi and bronchioles (lower respiratory tract) of newborns or, in any case, of children under 2 years of age with a higher prevalence (prevalence) in the first 6 months of life.
The greatest number of new cases (incidence) occurs between November and March.
Usually, healing occurs spontaneously without any cure. Rarely, hospitalization is required.
The first symptoms (symptoms) caused by bronchiolitis are similar to those of a common cold: runny nose (rhinorrhea), nasal inflammation (rhinitis) and cough, often accompanied by low-grade fever.
Subsequently, the cough may become persistent and tend to worsen gradually. Breathing can become rapid and noisy (dyspnea) and can be characterized by intercostal indentations (the dimple in the neck just above the breastbone and the spaces between the ribs, with each inhalation, are retracted).
In most cases, healing is spontaneous, requiring no cure, and the disease resolves without consequences within a dozen days.
However, a decrease in blood oxygen levels often occurs in babies under six months of age. In infants under 6 weeks of age, in premature births or in infants with persistent (chronic) diseases, the risk of prolonged breathing pauses (apnea) increases.Difficulty breathing together with refusal to eat can cause dehydration to be more or less worrying.
In these cases, to keep hydration and the functioning of the heart and lungs under control (cardio-respiratory function), the treating pediatrician may recommend a possible hospitalization.
In 75% of cases the microorganism responsible for bronchiolitis is the respiratory syncytial virus (RSV), but the disease can also be caused by other viruses such as: metapneumovirus, coronavirus, rhinovirus, adenovirus, influenza and parainfluenza viruses.
The contagion occurs by direct contact. The incubation period can vary from 6 to 10 days.
Bronchiolitis is diagnosed by the pediatrician through the examination and observation of the disorders (symptoms).
If the patient's condition appears worrying, the doctor may prescribe laboratory and / or instrumental tests such as, for example, the search for respiratory viruses in the secretions of the nose and throat (nasopharyngeal aspirate), the measurement, in arterial blood, of the quantity oxygen (O2), oxygen saturation (SaO2) and the amount of carbon dioxide (CO2) present to assess whether the body's oxygenation is good or hospitalization is required.
Very rarely, chest X-rays are required to check whether impaired breathing has caused complications in the lungs.
In most cases the evolution of the disease is benign, no treatment is needed and within 3 weeks recovery occurs.
Infants who have no difficulty in breathing and are able to feed can be followed at home by the treating pediatrician. If breathing is difficult, frequent nasal washes can be carried out, with aspiration of mucus, and aerosols with a so-called solution hypertonic 3% which, having a higher concentration of salts, draws the fluids to the surface of the bronchi and makes it easier to remove the mucus present.
It may be advisable to use inhaled bronchodilators 3-4 times a day if, after a first administration, an effective improvement in breathing is evident, otherwise, their use is not recommended.
Cortisone is sometimes prescribed by mouth (orally) but in the most recent scientific literature no improvement is described in children undergoing this therapy.
The use of antibiotics, if no bacterial infections are present, is not recommended.
To overcome the difficulty of children in eating it may be useful to reduce the amount of food and increase the frequency of meals.
To improve breathing and hydration, children admitted to hospital could be given both humidified and heated oxygen and saline solution with glucose into a vein (intravenously).
To reduce the risk of getting bronchiolitis, or, if the infection has already occurred, to avoid other infections or further worsen the health conditions, it is advisable to:
- provide an adequate amount of fluids
- never smoke indoors, even in environments where the child is not found
- always wash your hands before caring for the baby
- wash your nose frequently with physiological or hypertonic solution
- avoid associating with sick people affected by airway infections
- make monthly injections of antibodies against respiratory syncytial virus (they help limit the severity of the infection)
Even children who have successfully survived the disease may have an increased respiratory rate for several months, both awake and in sleep.
Babies born with premature birth, those under 12 weeks, those with congenital heart disease, bronchopulmonary dysplasia, cystic fibrosis, airway abnormalities already present at birth (congenital) and immunodeficiencies, if they are affected by bronchiolitis they may experience more or less serious respiratory problems such as blue discoloration of the mucous membranes and skin due to insufficient oxygenation (cyanosis), severe respiratory failure, penetration of air into the pleura and consequent inability of the lung to expand (pneumothorax), penetration of air into the mediastinum, an area in the center of the chest between the lungs (pneumomediastinum), or secondary bacterial infections that need to be treated separately.
In these cases, it is advisable to consider whether it is necessary to hospitalize the child.
Severe respiratory failure may require assisted breathing with intubation.
Respiratory syncytial virus (RSV) infections (relapses) may occur after the first episode but are generally not serious. It is suspected that recurrence of bronchiolitis could favor the onset of asthma at a later age, but the relationship between the two diseases is still unclear and therefore subject to further studies.
NHS Choices. Bronchiolitis (English)
Mayo Clinic. Bronchiolitis (English)