The common cold

Abstract

Many people experience colds during the fall. A cold is a viral infection of the upper respiratory tract and is one of the top five diagnosed conditions in the United States. They are the leading cause of work and school absenteeism. Most colds are self-limiting—symptoms usually resolve on their own in 7 to 14 days. The objectives of self-treatment are to reduce symptoms, improve functioning and sense of well-being, and prevent spread of the disease. Nonpharmacologic therapy is the mainstay of treatment. Because symptoms appear, peak, and resolve at different times, a stepwise approach using single-entity products targeting specific symptoms is preferable to the use of combination products. Patient education regarding the administration of I.N. and ocular drugs is important. Although evidence of efficacy is lacking, popular therapies include increased fluid intake, adequate rest, a nutritious diet as tolerated, and increased humidification with steamy showers, vaporizers, or humidifiers. Saline nasal sprays or drops moisten irritated mucosal membranes and loosen encrusted mucus. Salt gargles may ease sore throats. Hot tea with lemon and honey, chicken soup, and vegetable and other broths are also soothing. Medical devices, such as Breathe Right nasal strips, are marketed for temporary relief from cold- and allergy-related nasal congestion and stuffiness. These lift the nares open and enlarge the anterior nasal passages. Aromatic oils (e.g., camphor, menthol, eucalyptus) in products such as Vicks VapoRub (for patients aged 2 years and older) also ease nasal congestion and improve sleep by producing a soothing sensation. Nondrug therapy for all patients includes upright positioning to enhance nasal drainage. Proper hand hygiene reduces the transmission of cold viruses and is especially important during the current COVID-19 pandemic. Decongestants treat sinus and nasal congestion. They are adrenergic agonists (sympathomimetics) that constrict blood vessels, thereby decreasing sinusoid vessel engorgement and mucosal edema. Direct-acting (e.g., phenylephrine, oxymetazoline, tetrahydrozoline) bind directly to adrenergic receptors; indirect-acting (e.g., ephedrine) displace norepinephrine from storage vesicles in prejunctional nerve terminals; and mixed (e.g., pseudoephedrine) have both direct and indirect activity. Rhinitis medicamentosa (RM)—that is, rebound congestion—has been associated with use of topical decongestants. Depending on the active ingredient, therapy of 3 to 7 days is the accepted duration to avoid RM. Decongestants interact with numerous drugs including MAOIs, ergot derivatives, serotonin/norepinephrine reuptake inhibitors, anticholinergic agents, some antivirals, and others. Decongestants may exacerbate diseases sensitive to adrenergic stimulation, such as hypertension, coronary heart disease, ischemic heart disease, diabetes mellitus, hyperthyroidism, elevated intraocular pressure, and prostatic hypertrophy. Certain patients may use other products such as antihistamines, local anesthetics, systemic analgesics, and antitussives to treat cold symptoms such as sore throat, aches, fever, and nonproductive cough. Combination products are highly marketed and may be convenient, but this benefit must be weighed against the risks associated with taking unnecessary drugs. Drug use during pregnancy and lactation requires a balance between risk and benefit. Because most colds are self-limiting, many providers recommend nondrug therapy for treatment of bothersome but not life-threatening symptoms. FDA does not recommend nonprescription cold medications for children younger than 2 years because of the lack of efficacy and risk of misuse or overuse leading to adverse events and death. Providers should emphasize nondrug measures in children; if pharmacotherapy is necessary, parents should follow dosing instructions carefully and avoid combination products. FDA requires all liquid products to include a measuring device. When selecting a product, consider patient references, such as product formulation, flavor, frequency of use, and safety. Numerous complementary therapies are marketed for cold symptom management, including zinc and vitamin C. In vitro studies have shown these have a modest antiviral effect at best, and efficacy data remain inconclusive. Products that claim to strengthen the immune system such as Airborne, Emergen-C Immune+, and others have not been proved to be effective in preventing or treating colds. Not all patients should self-treat their colds. Those who have a temperature above 100.40F, are experiencing shortness of breath, have an underlying chronic cardiopulmonary condition, are frail or older adults, and infants aged 3 months or younger should be referred to their primary care provider.