Bronchiolitis is inflammation of the bronchioles.
acute b. A viral bronchiolitis occurring most commonly in children under the age of 2 years; marked by a hacking cough, difficult breathing, and wheezing resulting from damage to the bronchiole walls and formation of mucus plugs that trap air in the distal bronchioles; usually caused by a respiratory syncytial virus but other viruses may also be responsible.
b. fibrosa obliterans Inflammation of the bronchioles with obstruction caused by fibrous granulation tissue formed in the walls of the terminal bronchioles.
b. obliterans with organizing pneumonia A widespread inflammatory and fibrous obstruction of the bronchioles complicated by pneumonia and fibrous obstruction of the pulmonary air sacs.
viral b. See acute bronchiolitis.