Viral bronchiolitis in children: a common condition with few therapeutic options

Even though bronchiolitis is a disease that has been recognized for many years, there are still few therapeutic strategies beyond supportive therapies. Bronchiolitis is the most frequent cause of hospital admission in children less than 1 year of age. The incidence is estimated to be about 150° million cases a year worldwide, and 2-3% of these cases require hospitalization. It is acknowledged that viruses cause bronchiolitis, but most of the studies focus on RSV. The RSV causes a more severe form of bronchiolitis in children with risk factors including prematurity, cardiovascular disease and immunodeficiency. Other viruses involved in causing bronchiolitis include RV, hMPV, hBoV and co-infections. The RV seems to be associated with a less severe acute disease, but there is a correlation between the early infection and subsequent wheezing bronchitis and asthma in later childhood and adulthood. The supportive therapies used are intravenous fluids and oxygen supplement administered by nasal cannula or CPAP in most complicated patients. Additional pharmacological therapies include epinephrine, 3% hypertonic saline and corticosteroids. The Epinephrine seems to have the greatest short-term benefits and reduces the need of hospital admission, whereas hypertonic saline and corticosteroids seem to reduce the length of hospital stay. As bronchiolitis is such a prevalent disease in children and RV seems to play an important role, perhaps more studies should center around the RV's contribution to the initial disease and following pathology.