Coryza, commonly known as the common cold, is a mild viral infection of the upper respiratory tract, mainly affecting the nose and throat. It is self-limiting and usually resolves within 7 to 10 days without the need for specific treatment. Despite being a benign condition, it contributes significantly to lost work and school days and can lead to complications, particularly in vulnerable groups.
Causes
The common cold is mainly caused by viruses, with over 200 different types identified. The most common viruses include:
- Rhinoviruses (majority of cases)
- Coronaviruses (other than COVID-19 types)
- Respiratory syncytial virus (RSV)
- Adenoviruses
- Parainfluenza viruses
Pathophysiology
The virus enters the body via the nose or mouth and attaches to the lining of the respiratory tract. The body’s immune system responds by producing inflammation, leading to increased mucus production, swelling of nasal tissues, and sneezing. Symptoms arise from both the direct viral damage and the immune response. The infection remains limited to the upper airways unless complications arise.
Signs and Symptoms
- Nasal congestion or blocked nose
- Runny nose (rhinorrhoea)
- Sneezing
- Sore throat
- Cough
- Mild headache
- Fatigue or feeling unwell (malaise)
- Low-grade fever (more common in children)
Risk Factors
- Close contact with infected individuals (e.g., schoolchildren, healthcare workers)
- Poor hand hygiene
- Weakened immune system (e.g., elderly, chronic illnesses)
- Exposure to cold weather or seasonal changes
- Smoking (impairs mucociliary clearance in the respiratory tract)
- Crowded environments (public transport, day-care centres)
Investigations
Routine investigations are not needed for the diagnosis of common cold as it is clinically diagnosed. However, in certain cases:
- Nasopharyngeal swabs: May be used to detect specific viruses during outbreaks or in vulnerable populations
- Chest X-ray: Only if there is suspicion of secondary bacterial infection (like pneumonia)
- Blood tests: Full blood count or CRP may be considered if there is clinical uncertainty or concern about complications
Management
1. Non-Pharmacological Management
- Rest and hydration: Crucial to aid recovery
- Steam inhalation: May help relieve nasal congestion (though evidence is limited)
- Saline nasal drops or sprays: Especially useful in children to clear nasal passages
- Good hygiene: Handwashing to prevent spread to others
- Use of tissues: To contain respiratory secretions and dispose of them properly
2. Pharmacological Management
- Paracetamol or ibuprofen: For fever, headache, and sore throat relief
- Decongestants: Short-term use of nasal sprays or oral decongestants to relieve blocked nose (should not be used for more than 5-7 days)
- Cough syrups: Not routinely recommended in children under 6 years, limited evidence of benefit
- Antibiotics: Not indicated for viral infections unless there is evidence of secondary bacterial infection
- Antiviral drugs: Not used in uncomplicated cases of the common cold
3. Surgical Management
There is no role for surgery in the management of uncomplicated common cold. Surgery may be indicated for complications (e.g., sinus surgery for chronic sinusitis) but this is rare.
Complications
- Secondary bacterial infections (e.g., sinusitis, otitis media, pneumonia)
- Asthma exacerbations in individuals with underlying asthma
- Dehydration, especially in young children and elderly
- Chronic cough or persistent nasal symptoms (post-viral)
References
- NICE Clinical Knowledge Summary (CKS): Common Cold (2022)
- Royal College of General Practitioners (RCGP) Guidance on Upper Respiratory Infections
- Public Health England Infection Prevention and Control Guidance
- GMC Good Medical Practice: Managing Viral Infections Safely
- NHS Inform: Common Cold Advice and Management