Difference Between Bronchiolitis and Pneumonia

Bronchiolitis and pneumonia are two respiratory tract infections encountered commonly. These two conditions share some features while being different due to some. When doctors inform the probable diagnosis, a clear understanding on the part of the patient is very important to avoid confusion and unnecessary concern.


Bronchioles are smaller airways that branch off small bronchi. These are intermediate to small diameter airways. Bronchioles subdivide extensively down to the levels of alveolar ducts. Bronchiolitis involves inflammation of these small airways. Bronchiolitis is a common condition in children and some children can get very sick with bronchiolitis. Patients with bronchiolitis present with features close to pneumonia. Cough, sputum, fever and pleuritic type chest pain are some of the clinical features of bronchiolitis. There is a component of obstruction, as well. Therefore, most of the cases have a mixture of features of pneumonia and obstructive airway disease. In children, the cough associated with bronchiolitis is very unique. It is a barking cough which may or may not be associated with hemoptysis. On examination, the child looks ill, dehydrated, febrile, and has chest recessions indicating an obstructive component. Sick child should be given oxygen while monitoring saturation, antibiotics first empirically and then with investigation evidence. The spirometry will show a slightly low Forced Expiratory Volume for the 1st second, which indicates an obstructive component of the condition and a normal Forced Vital Capacity. Peak flow will be low in airway obstruction. Full blood count, blood culture, sputum culture and chest X-ray may be done as needed.

Treatments for bronchiolitis include antihistamines, bronchodilators, steroids and oxygen therapy. Bronchitis may lead to pneumonia, lung abscess, pleural effusion and systemic infection.


Pneumonia may occur as a complication of bronchitis, bronchiolitis, upper airway infections, or as a primary infection. Pneumonia is due to inflammation of alveoli and terminal airways. Inflammation may be due to infection or allergic reactions. Clinical features of pneumonia are fever, cough, sputum, hemoptysis, pleuritic type chest pain, difficulty in breathing and ill health. Pneumonia can be complicated by lung abscess, respiratory failure, pleural effusion and septicemia. Patient may present acutely ill or with minor features. Investigations are similar to those done in bronchiolitis. Findings may also be the same. The complete picture is necessary to differentiate between bronchiolitis and pneumonia. Treatment principles for pneumonia are very similar to bronchiolitis, as well.

Pneumonia vs Bronchiolitis

• Bronchiolitis is inflammation of small airways while pneumonia is inflammation of alveoli.

• Both conditions share infective etiologies.

• Bronchiolitis is commoner in children compared to pneumonia.

• Bronchiolitis causes effusions less frequently than pneumonia.

• It is not common for pneumonia to progress into bronchiolitis while the reverse is very common.