COMMON COLD

The common cold is a highly contagious infection (usually caused by rhinoviruses) that is spread by coughing and sneezing. Infection typically lasts 4-10 days.

Overview

Acute viral nasopharyngitis, often known as the common cold, is a mild viral infectious disease of the upper respiratory system (nose and throat).

Symptoms include sneezing, sniffling, stomach aches, runny nose, nasal congestion; scratchy, sore, or phlegmy throat; coughing; headache; and tiredness. Those affected may also feel achy.

Colds typically last three to five days, with residual coughing and/or catarrh lasting up to three weeks. The common cold is the most common of all human diseases, infecting adults at an average rate of 2 - 4 infections per year, and school-aged children as many as 12 times per year. Infection rates greater than three infections per year per person are common in some populations. Children and their parents or caretakers are at a higher risk, possibly due to the high population density of schools and because transmission to family members is highly efficient.

The common cold belongs to the upper respiratory tract infections. It is different from influenza, a more severe viral infection of the respiratory tract that shows the additional symptoms of rapidly rising fever, chills, and body and muscle aches. While the common cold itself is rarely life-threatening, its complications, such as pneumonia, can be.

Symptoms

Between a third and a half of people exposed to a cold virus become infected; 75% show symptoms, which start 1-2 days after infection.

Generally, a cold starts with a sore throat with no respiratory blockage. Later symptoms are a result of the body's defense mechanisms -- sneezes, runny nose, and coughs. Coughs expel the invader while inflammation attracts and activates immune cells. Severe colds can even lead to a slightly stiff neck and mild to severe headaches with a slight fever for some.

Often confused with influenza, the common cold is caused by a different type of virus and usually does not result in a significantly higher body temperature -- a high fever is a very reliable indicator of the flu.

After a common cold, a sufferer develops immunity to the particular virus. This immunity offers only limited protection against the many other cold viruses. The person, therefore, can easily be infected by a different cold virus.

Complications

Bacteria that are normally present in the respiratory tract can take advantage of the weakened immune system during a common cold and produce a coinfection. Middle ear infection (in children) and bacterial sinusitis are common coinfections. A possible explanation for these coinfections is that strong blowing of the nose drives nasal fluids into those areas.

The best way to blow the nose is keeping both nasal openings open when blowing and wiping rather than fully covering them, permitting pressure to partially dissipate. Doing so will reduce the pressure that would otherwise drive into the ears or sinuses.

Prevention

The best way to avoid a cold is to avoid close contact with existing sufferers; to wash hands thoroughly and regularly; and to avoid touching the face. Anti-bacterial soaps have no effect on the cold virus - it is the mechanical action of hand washing that removes the virus particles.

Treatment

There is no cure for the common cold. Treatment is limited to symptomatic supportive options, maximizing the comfort of the patient, and limiting complications and harmful sequelae.

Since the common cold is caused by a viral infection, antibiotics will have no effect on the virus.

The most effective treatment is a combination of adequate fluid intake, simple analgesia (eg. paracetamol), and rest.