Common cold

The common cold, also referred to as acute viral nasopharyngitis, is a ubiquitous viral infection of the upper respiratory tract affecting the nasal mucosa, throat, sinuses, and larynx. Symptoms typically manifest within two days of exposure and include coughing, sore throat, runny nose, sneezing, headache, and fever.

Recovery usually occurs within seven to ten days, though some symptoms may persist for up to three weeks. In individuals with compromised health, complications like pneumonia can arise.

Signs and Symptoms

The hallmark symptoms of a cold include a runny nose, nasal congestion, cough, and sore throat, sometimes accompanied by muscle ache, fatigue, headache, and loss of appetite. Fever is rare in adults but common in children.

Progression

A cold typically starts with fatigue, chills, sneezing, and headache, progressing to a runny nose and cough within a couple of days. Symptoms peak around two to four days after onset and usually resolve within a week to ten days, though a post-viral cough can linger for weeks. In children, cough may persist for more than ten days in 35–40% of cases and for more than 25 days in 10%.

Causes and Transmission

The common cold can be caused by over 200 different viruses, with rhinoviruses being the most prevalent. Other causative agents include coronaviruses, adenoviruses, and enteroviruses. Transmission occurs through airborne droplets, direct contact with infected secretions, or contaminated objects.

Diagnosis

Diagnosis is predominantly based on clinical symptoms. Isolation of the virus is rare and unnecessary for managing the condition. The differential diagnosis includes allergic rhinitis, bronchitis, bronchiolitis, pertussis, and sinusitis.

Prevention

Effective preventive measures include proper hand washing, using face masks, and practising cough etiquette. There is no vaccine for the common cold due to the multitude of viruses and their rapid mutation rates. Maintaining good hygiene practices and avoiding close contact with infected individuals are key preventive strategies.

Management

Management focuses on symptomatic relief as there is no cure for the common cold. Recommended conservative measures include rest, hydration, and gargling with warm salt water. Medications like NSAIDs can alleviate pain and fever, though the effectiveness of acetaminophen remains unclear. Over-the-counter cough medicines are not recommended for children due to potential harm and lack of proven benefits.

Symptomatic Treatment

Short-term use of nasal decongestants and antihistamines can provide temporary relief. However, the benefits of increased fluid intake and heated air treatments are inconclusive. Physical exercise is generally safe if symptoms are confined to the head.

Antibiotics and Antivirals

Antibiotics are ineffective against viral infections and should not be used. There are no licenced antiviral drugs for the common cold as of now, although research is ongoing.

Zinc and Alternative Medicine

Zinc supplements may reduce the duration and severity of cold symptoms if taken within 24 hours of onset. However, some zinc treatments can cause adverse effects like loss of smell. Alternative medicines, including herbal remedies and vitamins, generally lack sufficient evidence to support their use.

Prognosis

The common cold is typically mild and self-limiting. Most people recover within a week, although some symptoms can persist for longer. Serious complications are rare and usually occur in the very old, very young, or immunocompromised individuals.

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Self-assessment MCQs (single best answer)

Which of the following is NOT typically a symptom of the common cold in adults?

What is the most common group of viruses that cause the common cold?

How many days after exposure do symptoms of the common cold typically manifest?

Which of the following is NOT a recommended conservative measure for managing the common cold?

Which diagnostic method is primarily used to diagnose the common cold?

Which of the following is an effective preventive measure for the common cold?

For how long can a post-viral cough linger after the other symptoms of the common cold have resolved?

Which of the following is NOT recommended for children with the common cold due to potential harm and lack of proven benefits?

What percentage of children experience a cough that persists for more than ten days after a cold?

Which supplement may reduce the duration and severity of cold symptoms if taken within 24 hours of onset, despite some adverse effects?