Bronchitis - Uncomplicated Acut

Definition

Acute bronchitis is a self-limiting inflammation of the large airways, usually caused by viral infection, characterized by cough with or without sputum production, lasting less than 3 weeks in otherwise healthy individuals.

Epidemiology

• Common worldwide, especially in fall and winter seasons
• Affects all age groups, more frequent in adults
• Accounts for a significant proportion of outpatient visits for respiratory complaints
• Most cases are viral and resolve without antibiotics
• Incidence peaks during viral respiratory infection outbreaks

Etiology

• Viral infections: influenza, parainfluenza, adenovirus, respiratory syncytial virus, coronavirus, rhinovirus
• Bacterial infections less common: Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordetella pertussis
• Environmental factors: tobacco smoke, air pollutants, occupational irritants
• Recent upper respiratory tract infection
• Allergic airway inflammation may contribute in some cases
• Predisposing comorbidities: asthma or chronic lung disease

Pathophysiology

• Viral infection causes inflammation of bronchial mucosa
• Edema and increased mucus production lead to cough
• Airway hyperresponsiveness may persist for weeks
• Secondary bacterial infection can occur in some cases
• Resolution occurs as immune system clears infection
• Ciliary dysfunction contributes to prolonged cough
• Inflammation is usually confined to large airways without alveolar involvement