Common cold

Clinical course and diagnosis

Symptoms caused by colds typically last for 1 to 2 weeks, and most patients will feel better after the first week. Tests are of no use in diagnosing the common cold.

Only a tiny proportion of common cold cases do not resolve spontaneously. Complications, which are rare, can occur in infants, the very old, and immunocompromised and chronically ill people.

Symptoms and signs of the common cold include the following:

• rhinorrhea,

• nasal obstruction,

• throat irritation or laryngitis,

• cough but normal chest examination, and

• fever.

Treatment

Despite many media claims, there is really no evidence that any medication produces more than minimal relief of symptoms or duration of illness.

• Cough suppressants. Antitussives relieve cough in adults. Over-the-counter cough syrups relieve symptoms in schoolchildren; however, there is no evidence that over-the-counter medication is effective in preschool children.

• Antihistamines. There is no evidence of benefit from treatment with antihistamines.

• Decongestants. Decongestants relieve cold symptoms.

• Antipyretics and nonsteroidal anti-inflammatory drugs. These drugs can relieve fever and headache, but do not affect the cold’s clinical course.

• Echinacea. There is no evidence of Echinacea being effective in treating colds.

• Vitamin C. Vitamin C can reduce the duration of a cold by less than half a day.

• Zinc. Zinc can reduce the duration of a cold slightly, but there is no consistent evidence of benefit.

• Comfort measures. Steam inhalation relieves cold symptoms, but there is no good evidence for other comfort measures.

• Antibiotics. There is no evidence of effectiveness in treating a cold with antibiotics.

Prevention

Results of a Canadian trial suggested that taking ginseng polysaccharides daily all winter would prevent 1 cold (and would probably cost more than $100). Although the results of this study have received much hype in the media, ginseng (marketed as COLD-fX) is probably no more effective at preventing colds than hand washing after contact with a cold sufferer. It is also worth remembering that the studies that advocate frequent hand washing and avoidance of contact with cold sufferers were done using weak methods.

Vitamin C has no preventive effect for most people; however, it can benefit athletes or heavy labourers slightly.

• Hand washing. Hand washing is effective in preventing the spread of colds.

• Echinacea. Echinacea has a possible small preventive effect.

• Vitamin C. Vitamin C has no preventive effect.

• Ginseng. Ginseng can have a small preventive effect.

• Vaccines. There are no effective vaccines to prevent colds.