The common cold

The common cold is a conventional term for a mild upper respiratory illness, the hallmark symptoms of which are nasal stuffiness and discharge, sneezing, sore throat, and cough1.
The common cold is mostly caused by viruses. Rhinoviruses have been found to be the most common cause in all age. More than 100 different serotypes of rhinoviruses have been identified. Viral infection of the nasal mucosa results in vasodilation and increased vascular permeability, which in turn cause nasal obstruction and rhinorrhoea, which are the main clinical symptoms of the common cold1.
                    Viral cause of the common cold1
Virus Estimated annual proportion of cases
Rhinoviruses 30-50%
Coronaviruses 10-15%
Influenza viruses 5-15%
Respiratory syncytial virus 5%
Parainfluenza viruses 5%
Adenoviruses <5%
Enteroviruses <5%
Metapneumovirus Unknown
Unknown 20-30%
As the viral infection quickly spreads, the inflammatory cascade is activated. Infected cells signal the production of cytokines and chemokines (e.g., platelet-activating factor, leukotrienes, prostaglandins, and bradykinins) that activate inflammatory and immunocompetent cells. Generally, Clinical symptoms occur within 16 hours after infection2.
The mean duration of the common cold is 7–10 days, but in a proportion of patients some symptoms can still be present after 3 weeks1.

1.Rhinovirus infections typically start with a sore throat, which is soon accompanied by nasal stuffiness and discharge, sneezing, and cough. The soreness of the throat usually disappears quickly, 2.whereas the initial watery rhinorrhoea turns thicker and more purulent.
2.Other symptoms associated with the cold syndrome include hoarseness, headache, malaise, and lethargy. Myalgia is an occasional complaint in patients with colds.
3.Fever is an infrequent finding during rhinovirus infections in adults, but it is fairly common in children with upper respiratory infections of any cause.
1.Since the common cold is caused by a multitude of different virus types, that an effective universal treatment for this disorder has not been developed is understandable. The symptomatic treatment of colds has been aimed at relieving the most disturbing symptoms of the illness.
2.There are a host of nonprescription medications available to treat the complex of symptoms associated with the common cold including decongestants, antihistamines, antitussives, expectorants and analgesic-antipyretic.
3.Ibuprofen and acetaminophen are recommended antipyretic to be used in children which have good safety profiles.

1.  Terho Heikkinen, Asko J?rvinen. The common cold. THE LANCET. 2003, 361: 51-59.
2.  中國醫師協會呼吸醫師分會, 中國醫師協會急診醫師分會. 普通感冒規范診治的專家共識. 中華內科雜志. 2012, 51(4): 330-333.
3.  特殊人群普通感冒規范用藥專家組. 特殊人群普通感冒規范用藥的專家共識. 國際呼吸雜志. 2015, 35(1): 1-5.