Common cold
Exam Tips
- In OSCEs, diagnose clinically: routine swabs are not needed for uncomplicated colds.
- Discoloured/thicker nasal mucus alone does not prove bacterial infection.
- Key paediatric fever safety thresholds: <3 months with >=38°C and 3-6 months with >=39°C need careful risk assessment.
- Always screen for complications in at-risk groups (smokers, immunocompromised, asthma/COPD, significant comorbidity).
- Antibiotic stewardship point: explain why antibiotics are not routinely beneficial in viral URTI.
- Image-aided revision: review a labelled diagram of paranasal sinuses/osteomeatal complex and paediatric Eustachian tube anatomy in your ENT textbook to understand sinusitis and otitis complications.
Definition
The common cold is an acute, usually self-limiting viral infection of the upper respiratory tract, dominated by nasal symptoms (congestion, rhinorrhoea, sneezing), sore throat, and sometimes cough. It is caused by multiple virus families (most commonly rhinoviruses), so immunity is incomplete and repeated infections are common across life.
Pathophysiology
After inoculation of the nasal or nasopharyngeal mucosa (via direct contact or aerosols), respiratory viruses infect epithelial cells and trigger an innate inflammatory response (including cytokine release), causing mucosal oedema, increased mucus production, and sensory nerve irritation. This produces sore throat early, then rhinorrhoea/congestion and sneezing; cough often appears later due to postnasal drip and airway irritation. Large viral diversity (for example >100 rhinovirus serotypes) and short-lived strain-specific immunity explain frequent reinfection and the lack of a single curative or preventive therapy.
Risk Factors
- Younger age (especially preschool and school-age children)
- Close contact with children (household exposure, childcare settings)
- Winter season in the UK (with rhinovirus peaks in autumn/spring)
- Smoking (more severe and prolonged respiratory symptoms)
- Immunocompromise
- Comorbid disease increasing adverse outcomes: asthma, COPD, diabetes mellitus, congestive heart failure, cystic fibrosis, sickle-cell disease
Clinical Features
Symptoms
- Rapid onset over 1-2 days
- Sore/irritated throat (often earliest symptom)
- Nasal irritation, congestion, clear then thicker rhinorrhoea, sneezing
- Cough (often later; may persist after other symptoms settle)
- Malaise, hoarse voice/laryngitis
- Less commonly low-grade fever, headache, myalgia, reduced smell/taste, sinus/ear pressure
- In infants/young children: irritability, poor sleep/feeding due to nasal blockage, cough-induced vomiting
Signs
- Usually mild systemic upset with normal or mildly elevated temperature in adults
- In preschool children, fever 38-39°C can occur
- Mild non-tender cervical lymphadenopathy may be present
- Nasal mucosal swelling and discharge on examination
- Pharyngeal erythema may be non-specific; isolated severe sore throat without nasal symptoms suggests alternative diagnosis (e. g. streptococcal pharyngitis)
- Ear findings should be checked for acute otitis media (erythematous/cloudy/bulging tympanic membrane)
Investigations
Management
Lifestyle Modifications
- Explain self-limiting nature and expected duration; provide safety-net advice (worsening breathlessness, chest pain, confusion, dehydration, persistent high fever, or deterioration after initial improvement)
- Hydration, rest, and avoidance of smoke exposure
- Hand hygiene, cough/sneeze etiquette, and reduced close contact while most symptomatic to limit spread
- Saline nasal drops/sprays for nasal blockage (especially in children)
Pharmacological Treatment
Analgesic/antipyretic
- Paracetamol: adults 500 mg-1 g every 4-6 hours when needed (maximum 4 g in 24 hours)
- Paracetamol (children): dose by age/weight per product and BNFc; do not exceed 4 doses in 24 hours
Use for pain/fever relief only; check combination OTC products to avoid accidental paracetamol overdose.
NSAID (if appropriate)
- Ibuprofen: adults 200-400 mg up to three times daily with food (usual OTC max 1.2 g/day)
- Ibuprofen (children): weight-based BNFc dosing if needed
Avoid/caution in peptic ulcer disease, significant renal impairment, dehydration, NSAID-sensitive asthma, anticoagulant use, and late pregnancy.
Topical nasal decongestant (short course)
- Xylometazoline 0.1% nasal spray (adults and older children as per product): 1 spray each nostril 2-3 times daily for up to 7 days
Short-term only to prevent rebound congestion (rhinitis medicamentosa); avoid prolonged use.
Oral decongestant (selected adults)
- Pseudoephedrine 60 mg every 4-6 hours (maximum 240 mg/day)
Avoid in severe hypertension, significant cardiovascular disease, hyperthyroidism, glaucoma, urinary retention, and with MAOIs; may cause insomnia/palpitations.
Cough symptom relief
- Simple linctus (adult use per label)
- Honey 1/2 to 1 teaspoon at night for children >1 year
Do not give honey to infants under 1 year (botulism risk). Evidence for cough medicines is modest.
Antibiotics
Not indicated for uncomplicated viral common cold; consider only if clear bacterial complication develops.
Complications
- Acute otitis media (especially common in younger children)
- Acute sinusitis (more likely with prolonged nasal obstruction/facial pain)
- Lower respiratory tract infection (acute bronchitis, pneumonia)
- Exacerbation of asthma or COPD
- In infants, especially preterm: bronchiolitis, croup, or pneumonia
- Secondary bacterial superinfection after initial viral illness
Prognosis
Overall prognosis is excellent: symptoms typically peak at day 2-3 and then improve. Most adults and older children recover in about 1 week, younger children often in 10-14 days, and cough can persist up to 3 weeks. Smokers tend to have more severe/prolonged symptoms and a higher risk of lower respiratory complications.
Sources & References
🏥BMJ Best Practice(2)
✅NICE Guidelines(1)
- Common cold[overview]
📖Textbook References(2)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1499)[context]
- Oxford Handbook of Clinical Diagnosis (Huw Llewelyn, Hock Aun Ang, Keir Lewis etc.) (Z-Library).pdf(pp. 507, 508)[context]