Transmission of the infection

• This is caused by inhalation of airborne respiratory droplets from people infected with the virus.
• It possibly also occurs by direct contact with infectious secretions. Some viruses may be spread by hand contact.
• Transmission most commonly occurs in the home, in schools, and in daycare centres. The main reservoir of viruses is in young children.

Epidemiology

• Adults have an average of between two and four colds a year. Children have up to 12 colds a year. Young children in nursery schools may average up to nine colds during the winter months.
• Adults with children at home have more colds than people without children.
• Annual epidemics occur within the colder months in temperate climates and during the rainy season in the tropics.^[2]

Presentation

• The most frequent symptoms are nasal discharge, nasal obstruction, sore throat, headache, and cough. Hoarseness, loss of taste and smell, mild burning of the eyes, and a feeling of pressure in the ears or sinuses due to obstruction and/or mucosal swelling may also occur.
• Cough is associated with 30% of colds and tends to start on about the 4th or 5th day when nasal symptoms decrease.^[2]
• There may be a mild increase in body temperature. Infants and young children are more likely to develop higher temperatures.
• In infants there may be irritability, snuffles resulting in difficulty feeding, and diarrhoea. Diagnosis may be difficult and fever can be the main symptom during the early part of the illness.

Differential diagnosis

• Adults:
  • Allergic rhinitis: nasal itching, sneezing, watery rhinorrhoea, and nasal obstruction. It is also often accompanied by itchy, watery eyes. It can be perennial, seasonal, or due to occupational exposure.
  • Non-allergic rhinitis: presents with chronic nasal symptoms.
  • Pharyngitis: acute pharyngitis is caused by a variety of organisms, including the adenoviruses and Streptococcus pyogenes. This pharyngitis is often more severe than the mild-to-moderate pharyngeal discomfort in the common cold.
  • Influenza initially presents with systemic symptoms, including fever, rigors, headaches, myalgia, malaise, and anorexia.
• Children:
  • In addition to the above list, consider a foreign body in the nose. The discharge is unilateral, purulent, foul-smelling, and blood-stained.
• Infants:
  • Consider the possibility of a more serious condition, eg meningitis, septicaemia, pneumonia.

Management

See also the separate article Ill and Feverish Child.

• There are no drugs of proven benefit for the prophylaxis or treatment of the common cold. Therefore, medical management is centred around providing symptomatic relief.
• Antibiotic treatment of children with upper respiratory tract infection (URTI) does not alter the clinical outcome of the illness or prevent further complications.^[3]
• Ensure adequate fluid intake.
• Address any underlying concerns. Taking the time to educate people that colds are self-limiting and have no specific curative treatment may reduce anxiety and prevent unnecessary visits to the doctor in the future.

Drugs

• Recommend symptomatic treatment only. Drugs should have only a minor role in the management of simple viral URTIs.
• It is good practice to restrict the use of over-the-counter products for the treatment of cough and cold symptoms in children under two years old to the following:^[5]
  • Paracetamol or ibuprofen:
    • Paracetamol is an effective first-choice analgesic and antipyretic in most people. Aspirin (in adults) and ibuprofen (in children) are licensed to treat pyrexia. Aspirin has a higher incidence of adverse effects than ibuprofen.
    • Paracetamol or ibuprofen should be used for discomfort in children, such as when caused by sore throat, muscle pain or high fever. They should not be used just to 'treat' a high temperature. Fever is not harmful and may in fact have some benefit for simple viral infections.
  • Simple non-pharmacological cough mixtures for the treatment of coughs (eg paediatric simple linctus or those containing glycerol or honey and lemon). Over-the-counter cough mixtures have little or no evidence for efficacy in children. Honey and lemon is probably as good as any formulation.
  • Vapour rubs and inhalant decongestants which can be applied to children's clothing to provide relief of a stuffy or blocked nose for children and infants aged over three months. Saline (sodium chloride 0.9%) nose drops can be helpful, particularly in infants who are having difficulty feeding.
• The same principles can be applied to children over two years old, although there is a range of other over-the-counter cough medicines that may be given to children over two years old.^[5]
• Antihistamines: may improve a runny nose and sneezing, but there is no significant difference in overall symptoms.^[6]
• Decongestants (norephedrine, oxymetazoline): provide short-term (3- to 10-hour) relief of congestive symptoms.^[7] However, stopping decongestants often leads to rebound congestion.
• Other therapies:
  • Echinacea: there is limited evidence that some preparations of echinacea may improve cold symptoms compared with placebo.^[8]
  • Steam inhalation: there is insufficient evidence to assess its value in people with the common cold.^[9]
  • Vitamin C: there is limited evidence that vitamin C slightly reduces the duration of cold symptoms.^[10]
  • Zinc: a Cochrane review found that zinc, administered within 24 hours of the onset of symptoms, reduces the duration and severity of the common cold in healthy people. Zinc supplements taken for at least five months were found to reduce the incidence of colds, school absenteeism and prescription of antibiotics in children. Zinc lozenges can produce side-effects and no firm recommendations about the dose, formulation and duration could be made.^[11]

Complications

• Young children may develop bronchiolitis, viral pneumonia, and croup.
• Infants less than three months of age are particularly susceptible to developing secondary bacterial lower respiratory infections.
• Approximately 65% of people aged over 60 years, who live in the community and develop a rhinovirus infection, can be expected to develop a lower respiratory tract illness. If there is a co-existing chronic medical condition or the person smokes then this risk is increased.
• Acute otitis media occurs in 2% of people with a cold. The incidence positively correlates with the incidence of the common cold in children each year.
• Bacterial infection of the paranasal sinuses occurs in 0.5% of people with a cold.
• Asthma may worsen and present as an acute exacerbation.
• People with chronic obstructive pulmonary disease who have a rhinovirus infection are more likely to have a longer duration of illness, a more severe illness, and to cough for longer afterwards than those without lung disease.^[12]
• The common cold is a major cause of absenteeism from work and school.

Prognosis

• The median duration of a common cold is a week.
• Approximately 25% of colds will last up to two weeks and, in smokers with a rhinovirus infection, the cough is more likely to be troublesome and prolonged.
• Cigarette smokers are likely to have a more severe illness than non-smokers but do not have higher incidence of colds.

Prevention

• Preventing the spread of the common cold is very difficult but simple measures to prevent the spread of acute respiratory infections, such as handwashing (especially around younger children), wearing masks and wearing gloves, have been shown to be effective.^[13]
• People with colds should also avoid close contact (eg hugging, kissing) and avoid sharing towels and flannels. Children should be discouraged from sharing toys belonging to a child with a cold.