COMMON COLD

The common cold (also known as nasopharyngitis, rhinopharyngitis, acute coryza, or a cold) is a viral infectious disease of the upper respiratory tract which affects primarily the nose. Symptoms include coughing, sore throat, runny nose, and fever which usually resolve in seven to ten days, with some symptoms lasting up to three weeks. Well over 200 viruses are implicated in the cause of the common cold; the rhinoviruses are the most common.

Upper respiratory tract infections are loosely divided by the areas they affect, with the common cold primarily affecting the nose, the throat (pharyngitis), and the sinuses (sinusitis). Symptoms are mostly due to the body's immune response to the infection rather than to tissue destruction by the viruses themselves. The primary method of prevention is by hand washing with some evidence to support the effectiveness of wearing face masks.

No cure for the common cold exists, but the symptoms can be treated. It is the most frequent infectious disease in humans with the average adult contracting two to three colds a year and the average child contracting between six and twelve. These infections have been with humanity since antiquity.

SYMPTOMS

Symptoms of a common cold usually appear about one to three days after exposure to a cold-causing virus. Signs and symptoms of a common cold may include:

• Runny or stuffy nose
• Itchy or sore throat
• Cough
• Congestion
• Slight body aches or a mild headache
• Sneezing
• Watery eyes
• Low-grade fever
• Mild fatigue
• The discharge from your nose may become thicker and yellow or green in color as a common cold runs its course. What makes a cold different from other viral infections is that you generally won't have a high fever. You're also unlikely to experience significant fatigue from a common cold.

TREATMENT

There are currently no medications or herbal remedies which have been conclusively demonstrated to shorten the duration of infection.Treatment thus comprises symptomatic relief.Getting plenty of rest, drinking fluids to maintain hydration, and gargling with warm salt water, are reasonable conservative measures.Much of the benefit from treatment is however attributed to the placebo effect.

Symptomatic

Treatments that help alleviate symptoms include simple analgesics and antipyretics such as ibuprofen and acetaminophen/paracetamol.Evidence does not show that cough medicines are any more effective than simple analgesics and they are not recommended for use in children due to a lack of evidence supporting effectiveness and the potential for harm.In 2009, Canada restricted the use of over-the-counter cough and cold medication in children six years and under due to concerns regarding risks and unproven benefits.In adults there is insufficient evidence to support the use of cough medications.The misuse of dextromethorphan (an over-the-counter cough medicine) has led to its ban in a number of countries.

In adults the symptoms of a runny nose can be reduced by first-generation antihistamines; however, they are associated with adverse effects such as drowsiness.Other decongestants such as pseudoephedrine are also effective in this population.Ipratropium nasal spray may reduce the symptoms of a runny nose but there is little effect on stuffiness.Second-generation antihistamines however do not appear to be effective.

Due to lack of studies, it is not known whether increased fluid intake improves symptoms or shortens respiratory illness and a similar lack of data exists for the use of heated humidified air.One study has found chest vapor rub to be effective at providing some symptomatic relief of nocturnal cough, congestion, and sleep difficulty.

Antibiotics and antivirals

Antibiotics have no effect against viral infections and thus have no effect against the viruses that cause the common cold.Due to their side effects they cause overall harm; however, they are still frequently prescribed.Some of the reasons that antibiotics are so commonly prescribed include: people's expectations for them, physicians' desire to do something, and the difficulty in excluding complications that may be amenable to antibiotics.There are no effective antiviral drugs for the common cold even though some preliminary research has shown benefit.

Alternative treatments

While there are many alternative treatments used for the common cold, there is insufficient scientific evidence to support the use of most. As of 2010 there is insufficient evidence to recommend for or against either honey or nasal irrigation.Studies suggested that zinc, if taken within 24 hours of the onset of symptoms, reduces the duration and severity of the common cold in healthy people.Due to wide differences between the studies, further research may be needed to determine how and when zinc may be effective.Vitamin C's effect on the common cold while extensively researched is disappointing, except in limited circumstances, specifically, individuals exercising vigorously in cold environments.Evidence about the usefulness of echinacea is inconsistent.Different types of echinacea supplements may vary in their effectiveness. It is unknown if garlic is effective.A single trial of vitamin D did not find benefit.