Common cold is a self-limited viral infection of the upper respiratory tract characterized by rhinorrhea (runny nose) and nasal obstruction.
Common cold is a term used to describe infections of the upper respiratory tract caused by different viruses, although rhinoviruses, coronaviruses and respiratory syncytial virus are the most common ones. An average adult experiences common cold from 2 to 3 times a year, a child – 5 to 7 times a year. The disease usually develops between the early fall and late spring. This illness usually manifests with rhinorrhea, nasal obstruction and, less frequently – cough. There is no etiologic treatment for common cold, the disease usually resolves by itself within a week or so. Symptomatic treatment may be administered to reduce the severity of the symptoms and relieve bothersome signs.
Common cold is caused by the various viruses that are transmitted via direct contact, by the small and large-particle aerosols including rhinoviruses, coronaviruses, respiratory syncytial virus. Though influenza virus, parainfluenza, and adenovirus infections are also accompanied by the upper respiratory tract involvement they cause more prominent systemic symptoms and affect the lower respiratory tract.
Infection of the nasal lining causes its marked inflammation with extensive infiltration of the mucosa by inflammatory cells, as the result, the mucosa appears swollen with increased blood flow, increased vascular permeability and serum leakage into the nasal cavity. All of that contributes to nasal obstruction and rhinorrhea.
A cough may occur as reflex due to the throat irritation by the so-called postnasal drip (dripping of the mucus produced in the nasal cavity down the back of the nose and throat).
The throat soreness is associated mainly with rhinovirus infection as the virus provokes bradykinin synthesis by the inflammatory cells.
- Children younger than 6 years are more likely to catch the disease, especially if they are visiting kindergarten;
- Impaired immunity due to chronic stress, lack of sleep or other long-standing diseases;
- The disease typically during the fall and spring seasons;
- Smoking damages the mucosa of the upper respiratory tract so it promotes the virus adhesion and penetrance;
- Spending a long time in place of people gathering such as the cinema, school, etc during the epidemics increases exposure to viruses and, therefore, sets a significant risk of developing common cold;
Symptoms and signs of common cold include the following:
- Sore throat – usually appears the first and resolves quickly when nasal obstruction develops;
- Nasal dryness/irritation followed by nasal obstruction and rhinorrhea (runny nose) – nasal symptoms becomes dominant form the day 2 of the disease and last up to complete resolution;
- Sneezing – occurs due to irritation of the nasal mucosa;
- Cough – develops typically after the onset of nasal symptoms;
- Fever is not usual in common cold, even if it’s present it is usually low grade. High-grade fever, however, may develop in small children. Otherwise, it is rather suggestive of influenza, parainfluenza or adenovirus infection;
Common cold normally resolves by itself within a week or two.
- Acute otitis media (inflammation of the middle ear) was reported to occur in association with common cold;
- Less frequently sinusitis (inflammation of the paranasal sinuses) develops;
- Bronchitis and pneumonia may occur following common cold due to weaken immunity.
Laboratory studies aren’t administered routinely.
There is no specific antiviral treatment. Antibiotics should not be given routinely unless secondary bacterial infection accedes.
Topical vasoconstrictors and antihistamines are recommended to lessen nasal congestion and mucus discharge. Systemic antihistamines lessen sneezing and rhinorrhea. Mild analgesics (acetaminophen, ibuprofen) may be taken to relieve throat soreness, headache, and fever. Throat-soothing demulcents (honey, antihistamines, decongestants) may also help to reduce cough.
Hand washing is considered the most efficient preventive measure. Echinacea, zinc supplements, vitamins C, D, and E are also sometimes recommended in order to prevent the disease.
There is no available vaccination against common cold, although during the influenza epidemics immunization against the specific strain present in that period helps to reduce the risk of catching influenza.