Bronchiolitis is an acute viral infection of the lower respiratory tract—specifically the bronchioles, the smallest airways in the lungs—that primarily affects infants under 1 year of age and young children. In 70 to 80 percent of cases, it is caused by the highly contagious respiratory syncytial virus (RSV), which spreads through direct contact with an infected person’s nasal secretions or through contaminated hands. Other viruses can also cause similar symptoms (rhinovirus, human metapneumovirus, coronavirus). Bronchiolitis is strictly seasonal: it occurs annually from November through March in the Northern Hemisphere, peaking in December–January. Preventing winter respiratory infections is the first line of defense. Care products for infants and children are available in the natural children’s careline.
Bronchiolitis is not a bacterial illness—antibiotics are completely ineffective and should not be used. In infants younger than 6 weeks, premature infants, and children with congenital heart disease or pulmonary bronchodysplasia, bronchiolitis can rapidly progress to a severe form requiring hospitalization.
Bronchiolitis typically begins like a cold (runny nose, mild cough, moderate fever < 38.5 °C) and then worsens within 48 to 72 hours as the bronchioles become affected: a dry, persistent cough, rapid breathing (tachypnea), wheezing, and difficulty feeding. These signs require a medical evaluation within 24 hours.
Call 15 immediately if any of the following serious signs are present:
For mild to moderate cases (normal feeding, respiratory rate < 60/min, no cyanosis), home care is possible under close parental supervision. Essential measures include dividing meals into smaller, more frequent feedings (to prevent fatigue during feeding),adequate hydration, clearing the nasal passages with saline rinses before each meal and before bedtime, and keeping the infant in a semi-upright position (30 to 45 °C). Respiratory physical therapy—previously recommended—has not been routinely recommended by the HAS since 2019; it may be indicated in cases of severerespiratory congestion upon medical advice. Never use essential oils containing camphor, menthol, or eucalyptol in infants (neurotoxicity).
From a preventive standpoint, vitamin D3 (routine supplementation recommended for all infants—400 to 1,000 IU/day depending on breastfeeding status) strengthens the immune defenses of the respiratory mucosa. Pediatric probiotics (Lactobacillus reuteri DSM 17938, Lactobacillus rhamnosus GG) have been shown in several clinical studies to reduce the frequency and severity of respiratory viral infections in infants. Routine handwashing by caregivers (soap and water for 30 seconds) and avoiding contact with people who have colds during the epidemic season are the most effective preventive measures. Nirsevimab (Beyfortus®—a monoclonal antibody against RSV) has been recommended since 2023 for all infants born before or during the RSV season—check with your pediatrician or maternity ward for more information.
