Bronchitis and bronchiolitis are two similar sounding terms and often go hand in hand. Both conditions may present similarly, share etiology, investigations, and treatment principles. However, there are a few fundamental differences between bronchitis and bronchiolitis.
Bronchitis is the inflammation of bronchi. There are two main bronchi. They are divided into three on the right side and two on the left side. These lobar bronchi further subdivide into segmental bronchi. Bronchitis involves these large airways. Bronchitis is a very common condition especially in children. Bronchitis can come in two forms. They are short lasting acute bronchitis and long lasting bronchitis (asthma).
Bronchi may get inflamed due to a whole host of causes. Infective bronchitis may be due to viral (commonest), bacterial or fungal (in immunocompromised individuals). Allergic bronchitis occurs most commonly in atopic individuals. Environmental agents, which are usually not harmful to humans, may cause histamine release and an inflammatory reaction. Foreign bodies getting lodged in the lumen of one of these large airways may elicit an inflammatory response.
Bronchitis presents with difficulty in breathing, rapid breathing, noisy breathing, cyanosis, poor exercise tolerance, cough and sputum production. There may be subtle distinguishing features in the symptomatology which allow clinicians to make a diagnosis. In general, the obstruction of larger airways gives obstructive airways disease symptoms. The spirometry will show a low Forced Expiratory Volume for the 1st second and a normal Forced Vital Capacity. Peak flow will be low. Full blood count, blood culture, sputum culture and chest X-ray may be done as needed.
Treatmentsfor bronchitis include antihistamines, bronchodilators, steroids and oxygen therapy. Bronchitis may lead to pneumonia, lung abscess, pleural effusion and systemic infection.
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. Patients with bronchiolitis present with features close to pneumonia. Cough, sputum, fever and pleuritic type chest pain. 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. Symptoms and signs of bronchiolitis are more or less the same as in bronchitis. Investigations for bronchiolitis are the same ones done for bronchitis. Treatments for bronchiolitis are the same.
Bronchiolitis vs Bronchitis
• Bronchitis is inflammation of larger airways while bronchiolitis is inflammation of smaller airways.
• Bronchitis gives obstructive features while bronchiolitis is a mix of obstructive and pneumonia-like features.