Bronchiolitis is a common disease of the lower respiratory tract (the bronchioles). It occurs most often in the winter and most commonly found in children under 2 years of age.

Bronchiolitis is caused by viruses, most commonly RSV, but it may be due to allergy.

Bronchiolitis starts like a normal cold, with a runny nose and sneezing. After a few days, a child with bronchiolitis will develop a wheezy cough and trouble breathing, fussiness, poor feeding. Children with mild cases, especially those with a thick nasal mucus, may get some relief with a cool-mist vaporizer or nasal suctioning with saline drops and bulb syringe.

A child who has a lot of trouble breathing may need to go to the hospital for oxygen and fluids and breathing treatments.