Bronchiolitis

Bronchiolitis is blockage of the small airways in the lungs due to a viral infection. It usually only occurs in children less than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing problems. More severe cases may be associated with nasal flaring, grunting, or the skin between the ribs pulling in with breathing. If the child has not been able to feed properly, signs of dehydration may be present. Bronchiolitis is usually the result of infection by respiratory syncytial virus (72% of cases) or human rhinovirus (26% of cases). Diagnosis is generally based on symptoms. Tests such as a chest X-ray or viral testing are not routinely needed. Urine testing may be considered in those with a fever. There is no specific treatment. Supportive care at home is generally sufficient. Occasionally hospital admission for oxygen, support with feeding, or intravenous fluids is required. Tentative evidence supports nebulized hypertonic saline. Evidence for antibiotics, antivirals, bronchodilators, or nebulized epinephrine is either unclear or not supportive. About 10% to 30% of children under the age of two years are affected by bronchiolitis at some point in time. It more commonly occurs in the winter in the Northern hemisphere. The risk of death among those who are admitted to hospital is about 1%. Outbreaks of the condition were first described in the 1940s. In a typical case, an infant under two years of age develops cough, wheeze, and shortness of breath over one or two days. Crackles or wheeze are typical findings on listening to the chest with a stethoscope. The infant may be breathless for several days. After the acute illness, it is common for the airways to remain sensitive for several weeks, leading to recurrent cough and wheeze. Some signs of severe disease include: The term usually refers to acute viral bronchiolitis, a common disease in infancy. This is most commonly caused by respiratory syncytial virus (RSV, also known as human pneumovirus). Other agents that cause this illness include human metapneumovirus, influenza, parainfluenza, coronavirus, adenovirus, rhinovirus and mycoplasma. Children born prematurely (less than 35 weeks), with a low birth weight or who have congenital heart disease may have higher rates of bronchiolitis and are more likely to require hospital admission. There is evidence that breastfeeding provides some protection against bronchiolitis.