Acute Viral Respiratory Tract Infections

Covers the contiguous viral upper-airway → bronchial spectrum: the common cold, laryngitis, and acute bronchitis. All three are usually viral, self-limiting, and do not warrant antibiotics. See influenza, COVID-19, community-acquired pneumonia, tuberculosis and pertussis for the other respiratory infections, and paediatrics’ croup page.

Common cold (upper respiratory tract infection)

The most common cause of cough. Involves the nasal airways down to the larynx. Commonly caused by rhinovirus, parainfluenza virus, coronavirus, and RSV. Cough may persist for weeks after the acute illness resolves, due to ongoing bronchial inflammation and increased airway responsiveness.

Clinical features

• 24–48 hours of weakness, malaise and tiredness
• Sore, runny nose; sneezing; sore throat
• Slight fever
• Other symptoms: headache, hoarseness, cough

Management

• Rest, fluids
• Smoking cessation advice
• Paracetamol 1 g every 6 hours (children 15 mg/kg)

Laryngitis

Self-limiting inflammation of the larynx, including the vocal cords.

Clinical features

Hoarse voice, sore throat, dysphagia, plus accompanying URTI symptoms. Symptoms typically improve within 8 days.

Management

• Do not prescribe antibiotics — this is a viral, self-limiting condition.
• Rest (voice rest), humidification, analgesia.

Acute bronchitis

Acute inflammation of the tracheobronchial tree, usually following an upper respiratory tract infection. Over 90% of cases are viral. Usually mild and self-limiting in otherwise healthy adults, but can be more significant in patients with underlying comorbidities (e.g. COPD, where it may complicate into an infective exacerbation, often due to Haemophilus influenzae or Streptococcus pneumoniae).

Clinical features

• Predominant symptom is cough (± sputum) — presents with non-specific upper/lower respiratory tract infection symptoms, cough being the leading feature
• Wheeze and dyspnoea
• Scattered wheeze on auscultation
• Fever or haemoptysis are uncommon — consider an alternative diagnosis if prominent

Expected course

Cough lasts on average 2–3 weeks; resolves within 4 weeks in ~90% of patients. In around 10% it persists to 8 weeks, reflecting the time needed for bronchial inflammation to settle.

Differential diagnosis

Pneumonia, influenza, pertussis, asthma, heart failure.

Treatment

• Symptomatic treatment is the mainstay.
• Inhaled bronchodilators (e.g. salbutamol 2–4 puffs QID) for airflow limitation/wheeze.
• Antibiotics are not routinely indicated — reserve for evidence of acute bacterial infection (fever with increased sputum volume/purulence), or in patients with significant comorbidity (e.g. COPD).