Upper respiratory tract infection

URTI refers to acute infections of the nose, sinuses, pharynx, or larynx. They are among the most common conditions seen in primary care, usually viral and self-limiting, but occasionally complicated by bacterial superinfection or lower respiratory tract involvement.

📖 Introduction & Pathophysiology

• URTIs are usually caused by viruses (rhinovirus, coronavirus, adenovirus, RSV, influenza, parainfluenza).
• Transmission is via droplets or direct contact with contaminated surfaces.
• Virus infects the respiratory epithelium, causing inflammation, oedema, and increased mucus production.
• The inflammatory response leads to typical symptoms: sore throat, nasal congestion, rhinorrhoea, cough, malaise, and fever.
• Secondary bacterial infection can occur (e.g. Group A Strep pharyngitis, bacterial sinusitis, otitis media).

⚠️ Common URTI Subtypes

• Common cold (acute viral rhinitis): Nasal congestion, sneezing, rhinorrhoea.
• Pharyngitis / Tonsillitis: Sore throat, painful swallowing ± exudates.
• Sinusitis: Facial pain, nasal blockage, purulent discharge.
• Laryngitis: Hoarse voice, dry cough.
• Otitis media: Ear pain, fever, irritability in children.

🩺 Clinical Features

• Nasal congestion, rhinorrhoea, sneezing 🤧
• Sore throat, dysphagia
• Cough (dry or productive)
• Fever, malaise, headache
• Hoarseness (laryngitis)
• Tender cervical lymph nodes (especially with bacterial pharyngitis)

🔎 Investigations

• Mostly clinical – tests are rarely needed in simple URTI.
• Throat swab / rapid strep test → if bacterial pharyngitis suspected (Centor score ≥3).
• Nasopharyngeal swabs (PCR) → in outbreaks or immunocompromised patients.
• Bloods (FBC, CRP) only if systemic infection suspected.
• Imaging (sinus X-ray/CT) only if recurrent or complicated sinusitis.

💊 Management

• Supportive care: Rest, fluids, paracetamol/ibuprofen, saline nasal sprays, throat lozenges.
• Antibiotics: Not indicated in viral URTIs. Consider only if bacterial cause strongly suspected (e.g. strep throat, bacterial sinusitis, otitis media with systemic illness).
• Symptomatic relief: Decongestants (short course only), antihistamines (if allergic component), honey (for cough in children >1 year).
• Hospital referral: If severe systemic illness, airway compromise, dehydration, or complications (e.g. peritonsillar abscess, mastoiditis, orbital cellulitis).

⚠️ Complications

• Sinusitis → orbital cellulitis, intracranial infection.
• Pharyngitis → peritonsillar abscess (quinsy), rheumatic fever, post-streptococcal GN.
• Otitis media → mastoiditis, hearing loss.
• Laryngitis → airway compromise (rare, usually in children).

📚 Key Teaching Pearls

• Most URTIs are viral and self-limiting - antibiotics usually unnecessary.
• Use Centor/McIsaac score to assess streptococcal pharyngitis risk.
• Always consider red flags: severe sore throat with trismus, stridor, unilateral swelling (think quinsy or epiglottitis).
• Public health importance: major driver of antibiotic overuse and resistance.

🌡️ Case 1 - Viral Pharyngitis

• Scenario: 21-year-old with sore throat, low-grade fever, mild cough, and coryzal symptoms.
• Context: Exam shows erythematous pharynx without tonsillar exudate.
• Teaching Point: 💡 Most pharyngitis is viral - supportive care (fluids, analgesia) is appropriate; antibiotics are not indicated.

🌡️ Case 2 - Acute Sinusitis

• Scenario: 37-year-old with 10 days of nasal congestion, purulent discharge, facial pressure worse on bending forward.
• Context: Febrile, tenderness over maxillary sinuses.
• Teaching Point: 💡 Usually post-viral; treat conservatively unless symptoms persist >10 days or severe, when antibiotics may be considered.

🌡️ Case 3 - Viral Laryngitis

• Scenario: 28-year-old teacher with hoarse voice and dry cough after recent cold.
• Context: Afebrile, laryngeal erythema on exam, no stridor.
• Teaching Point: 💡 Common and self-limiting; managed with voice rest, hydration, and reassurance. Antibiotics have no role.