Contents of this article
What is Cold
The common cold is an acute, self-limiting, usually afebrile, viral infection that causes inflammation of the upper respiratory tract.
Causes of Cold
Common cold is mostly caused by viruses. About 95% results from a viral infection of the upper respiratory tract that cause inflammation of the mucous membrane. The most common causative agent is the rhinovirus; however, some colds result from Mycoplasma coronaviruses, myxoviruses, adenoviruses, coxsackieviruses, and echoviruses, respiratory syncytial virus (RSV), echovirus, Influenza virus, parainfluenza virus. The virus spreads through tiny, air droplets that are released from an infected persons when they sneezes, coughs, or blows their nose.
Predisposing factors of Cold
Many factors can increase your risk of catching a cold, including:
- Close contact with someone who has a cold
- Age (infants and young children have more colds per year than adults)
- Environmental changes (weather climate)
- Compromised immunity
Pathophysiology of Cold
The pathophysiology of the common cold involves several interconnected processes:
Viral Transmission:The most common viruses responsible for the common cold include rhinoviruses, coronaviruses, and respiratory syncytial virus (RSV). These viruses are typically transmitted through direct contact with infected respiratory droplets or contaminated surfaces.
Virus Attachment and Invasion:Once inhaled, the viral particles attach to specific receptors on the surface of nasal epithelial cells. For instance, rhinoviruses bind to intercellular adhesion molecule-1 (ICAM-1) receptors.
Local Inflammatory Response:After attachment and invasion into nasal epithelial cells, viral replication occurs within these host cells leading to their destruction. This process triggers an immune response characterized by local release of pro-inflammatory cytokines such as interleukins (IL-6, IL-8), tumor necrosis factor-alpha (TNF-alpha), and interferons (IFNs).
Vasodilation and Increased Vascular Permeability:Pro-inflammatory mediators cause vasodilation of blood vessels near affected areas resulting in increased blood flow to the nasal mucosa which contributes to congestion symptoms associated with a cold.
Nasal Secretions:In response to inflammation and irritation caused by viral infection, goblet cells in the respiratory epithelium secrete excessive mucus. This increased mucus production aims at trapping viruses along with other pathogens or irritants present in the airways
Ciliary Dysfunction:Cilia lining the respiratory epithelium play a crucial role in propelling mucus out from the nose towards throat for clearance but during a cold ciliary function may be impaired due to inflammation leading poor clearance capacity contributing further congestion.
Host Immune Response:The immune system mounts an antiviral response to eliminate the viral infection. This includes the release of interferons, which help inhibit viral replication and recruit immune cells such as neutrophils and natural killer (NK) cells to fight off the infected cells.
Duration and Resolution:The common cold typically lasts for a few days to a week as the host's immune system clears the viral infection. However, symptoms can persist longer in some cases or be prolonged by secondary bacterial infections.
Signs & Symptoms of Cold
Symptoms of a cold usually peak within 2 to 3 days after exposure to a cold virus and vary from person to person. People are most contagious for the first 2 to 3 days of exposure. It is most often not contagious after the first week. Symptoms include:
- Sore or scratchy throat.
- Cough
- Watery eyes
- Hoarseness of voice
- Sneezing.
- Fever and chills
- Muscle aching
- General malaise
- Nasal discharge
- Loss of appetite
- Croup
- Slight body aches or a mild headache
Diagnostic Investigations & Test
- Physical examination
- Signs and symptoms of cold
- Culture and sensitivity for bacterial
Management of Cold
Currently, there is no cure common cold. It's treated symptomatically. However, the following are some treatments that may help to relieve some symptoms of the cold:
- Adequate Rest
- Increased fluid intake
- Pain relievers for headache or fever
- Warm, salt water gargling for sore throat
- Antipyretics and analgesics e.g. Paracetamol for pain and fever
- Nasal decongestants e.g. ephedrine nasal drops to clear air for patency
- Cough expectorants e.g. Benylline cough mixture to suppress coughing
- Moist inhalation with menthol for congestive nose
- Antihistamines in cases of allergic rhinitis e.g. hydrocortisone to dry up nasal secretions and suppress coughing
Nursing Interventions of Cold
- Assess and monitor vital signs
- Isolate patient during the infective phase.
- Give adequate rest to patient to ensure symptoms relieved.
- Ensure serene environment and make patient bed free from cramps and creases.
- Ensure adequate ventilation
- Give well balanced diet
- Ensure adequate intake of liberal fluids
- Teach patient on proper disposal of tissue used for sneezing and coughing
- Encourage and teach on frequent hand washing with soap and water.
- Provide psychological support.
- Serve prescribed medications.
- Education patient and caregivers on the condition
- Encourage the client to avoid exposure to irritants
- Encourage the client to avoid contact with individuals with upper respiratory infections.
Complications of Cold
- Bronchitis
- Ear infection (otitis media)
- Pneumonia
- Sinusitis
- Lower respiratory tract infection (pharyngitis)
- Pharyngitis
- Laryngitis
- Bronchopneumonia
- Tracheitis
- Mastoiditis
Prevention of Cold
- Regular hand washing
- Avoid close contact with people who have colds or other upper respiratory infections.
- Cover your mouth and nose when coughing or sneezing.
- Avoid touching your eyes, nose, and mouth with unwashed hands.
- Avoid smoking
References
- Eccles R., Understanding Acute Nasal Congestion - Rhinology
- Turner RB et al., Pathogenesis of rhinovirus infections - Current Opinion Virology
- National Institute for Health and Care Excellence (NICE), Common Cold - Clinical Knowledge Summaries
