Bronchiolitis is a common lower respiratory tract infection in infants and young children, occurring exclusively in those under 2 years old, with most cases seen in babies aged 1 to 6 months. The condition is related to the anatomical characteristics of the bronchi at this age, where the tiny lumens are prone to obstruction by viscous secretions, edema, and muscle contraction, potentially leading to pulmonary emphysema or atelectasis. As a result, the clinical symptoms resemble pneumonia but with more pronounced wheezing and breathlessness. The disease is caused by various viruses, most commonly respiratory syncytial virus. Additionally, parainfluenza virus, adenovirus, and others can also be responsible, and mixed viral-bacterial infections may occur. The peak incidence occurs mainly in winter and spring.

bubble_chart Clinical Manifestations

The onset is relatively acute, with preliminary symptoms of a common cold, such as cough and sneezing. After 1–2 days, the cough worsens, accompanied by paroxysmal dyspnea, wheezing, pale complexion, cyanosis of the lips, and three depressions sign (+). Early lung signs are dominated by wheezing, followed by moist rales. In severe cases, it may be accompanied by congestive heart failure, respiratory failure, hypoxic encephalopathy, and water-electrolyte imbalances. Generally, the body temperature does not exceed 38.5°C, and the course of the disease lasts 1–2 weeks.

[Auxiliary Examination]

White blood cell count is mostly normal or shows a grade I increase. Blood gas analysis may reveal hypoxemia and altered partial pressure of carbon dioxide (either decreased or increased). Chest X-ray may show thickened lung markings, increased bilateral lung translucency, or small shadows and atelectasis. If conditions permit, rapid viral diagnosis of respiratory secretions can be performed to identify the specific virus type. [

(1) Age: It is more common in children under 1 year old, especially infants under 6 months. (2) Season: The disease can occur throughout the year but is more prevalent in winter and spring.

bubble_chart Treatment Measures

﹝Treatment﹞

(1) General Management Maintain airway patency, enhance dampness transformation, keep indoor temperature, humidity, and ventilation, provide oxygen therapy, suction sputum, turn the patient and pat the back, and increase ultrasonic aerosol inhalation. (2) Fluid Replacement The amount of fluid replacement depends on the degree of dehydration, generally around 100ml/kg per day. Correct water and electrolyte imbalances promptly and ensure caloric maintenance. (3) Symptomatic Treatment Sedation, dispelling phlegm, and relieving asthma. Short-term hormone therapy may be used for patients with severe asthma. Address complications promptly, such as actively controlling heart failure if it occurs. (4) Disease Cause Treatment Use antiviral drugs: Ribavirin, Double Coptis Rhizome, etc. Administer appropriate antibiotics in case of secondary bacterial infections.