Upper respiratory infection

By Brian S. Alper, MD, MSPH

January 12, 2010

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Also called

• Common cold, upper respiratory tract infection (URTI), acute rhinitis, acute nasopharyngitis, acute rhinosinusitis

ICD-9 codes

• 460 acute nasopharyngitis (common cold)
• 465.0 acute laryngopharyngitis
• 465.8 acute upper respiratory infections (URIs) of other multiple sites
• 465.9 acute URIs of unspecified site

Incidence

• Average U.S. adult has two to four colds per year; average schoolchild has 6-10 colds per year.
• URI is second most common diagnosis made at clinician visits (closely following hypertension).

Etiology

• Usual causative pathogen is rhinovirus or one of many other respiratory viruses.
• Transmitted by particle aerosol and hand contamination (followed by self-inoculation)
• Incubation period: two to four days

Likely risk factors

• Fall and winter
• Exposure to young children (e.g., day care)
• Cigarette smoking
• Psychological stress

History

• Symptoms: cough, fever, runny or stuffy nose, sore throat, pinkeye, earache, nasal discharge, nasal and pharyngeal erythema or edema, sneezing, sore “scratchy” throat, dry cough, hoarseness, headache, chills, cervical adenopathy
• Purulent rhinitis without unilateral maxillofacial pain may predict “sinusitis” on x-ray, but antibiotics not needed; most such cases are viral.

Physical examination

• May be normal or may reveal findings listed under “History”
• Look for signs of

— Otitis media: tympanic-membrane bulging, opacified or with limited mobility
— Pneumonia: rales, decreased breath sounds; tachypnea is most telling clinical sign in children.
— Streptococcal pharyngitis: fever, pharyngeal or tonsillar exudate, absence of cough
— Infectious mononucleosis: fever, sore throat, diffuse adenopathy

Diagnosis

• Diagnosis of nonspecific URI should be used for acute infection in which sinus, pharyngeal, and lower airway symptoms, although frequently present, are not prominent (CDC evidence-based guidelines).
• Clinical judgment not a good predictor of bacterial respiratory infection
• Imaging studies not indicated; radiographic sinusitis is common during the common cold.
• Low nasal swabs are less painful and as accurate as nasopharyngeal swabs in children.

Prognosis

• More than 50% of rhinoviral colds last longer than one week; up to 25% last more than two weeks.
• Complications rare

Treatment

• Effective symptomatic treatments (supportive therapy)

— Acetaminophen (650 mg p.o. every four hours as needed or 1,000 mg p.o. every six hours as needed) or nonsteroidal anti-inflammatory drugs (NSAIDs)

For pain, sore throat, symptomatic fever
Not necessary for asymptomatic fever
Acetaminophen preferred over NSAIDs

— Decongestants

Limited short-term benefit in adults

No benefit in young children
• Treatments with limited or inconsistent evidence

— Some antitussives (dextromethorphan, guaifenesin) in adults
— Ipratropium bromide (Atrovent) nasal spray
— Zinc: zinc gluconate lozenges, zinc acetate lozenges; use of intranasal zinc should be avoided, may lead to permanent loss of smell.
— Echinacea preparations have limited evidence suggesting benefit but insufficient evidence to recommend specific products
— Vitamin C
— Humidifier or vaporizer

• Medications that are not effective

— Antitussives in children
— Antihistamines
— Intranasal corticosteroids
— Antibiotics not indicated and could be harmful; not necessary for patient satisfaction as long as needs are addressed
— Goldenseal should not be used due to adverse effects and no evidence for efficacy.

• No effective licensed antivirals currently available
• Determining reason for office visit may help determine approach to patient

— If seeking relief, consider symptomatic therapies.
— If seeking reassurance (ruling out serious illness), focus on ruling out pneumonia, strep throat, and otitis media.
— If seeking cure (antibiotics), patient education and delayed prescriptions may be helpful.
— Work or school excuse might be primary reason for visit.

• Receiving information/reassurance more strongly associated with patient satisfaction than receiving antibiotics

Prevention

• Hand washing

— Associated with 45% reduction in outpatient visits for respiratory illness
— Antibacterial soaps no more effective than plain soap
— Use of instant hand sanitizer associated with reduced illness-related absenteeism among schoolchildren.

• Multivitamin and mineral supplementation

— May reduce incidence of infections in diabetics, based on randomized trial of 158 patients
— Does not reduce incidence of infections in elderly, based on randomized trial of 910 persons and meta-analysis of eight other randomized trials

• Vitamin C prophylaxis

— May modestly reduce duration and severity of common cold
— May prevent common cold during brief periods of severe physical exercise or cold temperature
— Evidence does not support routine use of megadose vitamin C (>1 g/day)

• Echinacea