children s health issues
Bronchiolitis
Introduction
Bronchiolitis is a viral infection that affects the lower respiratory tract of infants and young children under 24 months of age. Bronchiolitis usually is caused by viruses. Symptoms include runny nose, fever, cough, wheezing, and difficulty breathing. The diagnosis is based on symptoms and a physical examination. Most children do well at home and recover in a few days, but some need to be hospitalized. Treatment is primarily supporting the child through the illness with fluids and occasionally with oxygen. The airways resemble an upside-down tree. The trunk is the windpipe (trachea), which branches into large airways called bronchi. The bronchi themselves branch many times into smaller airways, ending in the smallest airways, which are called bronchioles. Bronchioles are as small as one half of a millimeter (or 2/100 of an inch) across. Their walls have a thin, circular layer of smooth muscle that can relax or contract, thus changing airway size. Bronchiolitis typically affects children younger than 24 months of age and is most common among infants younger than 6 months of age. During the first year of life, bronchiolitis affects about 11 of every 100 children. However, during some epidemics, a much higher proportion of infants are affected. Most cases occur between November and April, with a peak incidence during January and February. 