– A self-limiting, acute viral infection of the upper respiratory tract. The resulting inflammation involves the nasal passages, throat, sinuses, trachea, and bronchi.
Causes and Incidence
The common cold can be caused by one of many viruses. About 40% of cases are caused by the rhinovirus group. Spring and summer colds are often caused by picornaviruses, whereas fall colds are frequently caused by parainfluenza and winter colds by coronavirus strains. The mechanisms of spread are not clearly defined and may vary somewhat by viral type. Direct contact is implicated in rhinovirus colds; airborne infection by droplet is probably the mechanism in other viral strains. Colds are the leading cause of acute morbidity in the United States. Children average six to eight colds a year, whereas adults average two or three.
The pathogenesis of colds is still sketchy. The virus is deposited in the nasopharynx, where it moves to the adenoids and a rich bed of viral receptors. An inflammatory reaction is evoked, resulting in vasodilation, mucus production, coughing, and sneezing about 16 hours after initial infection. The virus spreads to the ciliated epithelial cells in the nasal passages, and symptoms continue for 4 to 10 days. The virus is active for about 3 weeks and may affect the trachea and bronchi, particularly in individuals with chronic respiratory disease.
Typical symptoms include nasal congestion and discharge, sore throat, sneezing, coughing, headache, and fatigue. Febrile reactions occur in infants and young children but are uncommon in older children and adults.
The most common complications are the secondary overlay of a bacterial infection with purulent sinusitis or otitis media and the triggering of bronchospasms in persons with asthma.
The diagnosis is made by clinical examination, while ruling out secondary bacterial sinusitis, otitis media, and streptococcal pharyngitis.
Acetaminophen analgesics for headache, nasal sprays for decongestion, saline gargle or topical anesthetics for sore throat; no aspirin for infants or children; no antibiotics.
Rest for comfort and to minimize spread; good handwashing and careful handling of items in the environment to minimize viral contact by others; adequate fluids for hydration.