The common cold is a viral upper respiratory infection. It accounts for at least one-half of all human illnesses. In the United States, adults average between 3 and 5.6 colds a year, while children have as many as 8.3.

More than 200 possible serologically different viruses cause colds. They are transmitted by respiratory droplets, hand-to-hand, or by object contact. Exposure to cold and fatigue do not increase susceptibility, although psychological stress may.

• Day care centers and office buildings
• Large family size
• Poor hygiene
• Psychological stress—can increase rate and severity

• Rhinorrhea, sneezing, nasal congestion
• Sore throat, cough, or hoarseness
• Fever (uncommon in adults, usually indicates flu or bacterial infection)
• In children, sudden onset of fever (lasting two to three days), irritability, restlessness, and sneezing
• Headache

• Asthma
• Sinusitis
• Pneumonia
• Bronchitis, bronchiolitis
• Flu
• Allergic rhinitis
• Children—initial symptoms of measles or pertussis; intranasal foreign body
• Infants—choanal atresia or congenital syphilis

The patient may be sneezing, have a runny nose, look fatigued, and complain of sore throat, rarely of diarrhea or vomiting.

Cultures are rarely done for diagnostic purposes but are performed for research.

Cultures determine the type of infection:

• Rhinoviruses—15% to 40% of colds; grows at 33 to 34°C (temperature of the nasal passages); one subtype, 100 serotypes
• Coronaviruses—10% to 20% of colds; three subgroups
• Adenoviruses—3% to 5% of children's colds, less than 2% of adults; six subgenera (A to F) and 47 serotypes
• Respiratory syncytial virus and parainfluenza viruses—can cause colds but more likely to cause lower respiratory tract infections, especially in children
• Edematous and hyperemic mucosa; hyperactive mucus glands
• Inflammatory cells include neutrophils, lymphocytes, plasma cells, and eosinophils.

Computed tomography scans may show bilateral abnormalities in the ethmoid and maxillary sinuses, with residual density possible in the maxillary sinus two weeks after resolution.

• Self-diagnosis is generally accurate.
• Diagnosis can be made only by isolation of the virus (e.g., by nasal wash), which is done almost exclusively for research purposes (e.g., rhinoviruses—grown in human embryonic lung fibroblasts).
• Antibodies for rhinovirus receptors are currently being researched.
• Experimental serotype vaccines are available but of little use given the large number of possible serotypes.

There is no known antiviral treatment for the common cold, which is generally benign and self-limited. Live vaccines exist for adenovirus types 4 and 7, primarily for use in the military. Antibiotics should not be given unless there are bacterial complications. Antihistamines are inappropriate and may increase and/or prolong congestion. Treatment is primarily to relieve symptoms.

• Nasal decongestants: may aid in preventing sinus and eustachian tube obstruction (e.g., pseudoephedrine 60 mg tid); general vasoconstriction may cause high blood pressure
• Nasal sprays: localized decongestant; rebound effect after three to five days
• Analgesics: can be used for malaise; may delay immune response or increase nasal symptoms; aspirin can cause Reye's syndrome in children
• Adequate hydration: loosens secretions
• Warm fluids and steam inhalation: provide symptom relief by increasing the rate of mucus flow
• Reduced activity: helps avoid complications

Alternative therapies offer effective symptom relief. General measures for treating infection are to get plenty of fluids and rest.

• Vitamin C (1,000 mg three to six times/day) enhances immune function (may affect interferon and interleukin); some studies show that it shortens the duration and ameliorates the symptoms of the common cold.
• Zinc (23 mg lozenges taken every two hours) may shorten the duration of a cold, and may also protect against the development of symptoms. This high a dose is for short-term use only.
• Vitamin A (25,000 IU/day) maintains integrity of mucous membranes and stimulates antibody response. Use high dose short-term only.
• Beta-carotene (200,000 IU/day) stimulates the immune system and is an antioxidant; safe in women of childbearing years.
• Avoid dairy and bananas, foods that increase mucus production.
• Garlic and onions are antivirals that can be included in the diet.

Herbs are generally a safe way to strengthen and tone the body's systems. As with any therapy, it is important to ascertain a diagnosis before pursuing treatment. Herbs may be used as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, teas should be made with 1 tsp. herb per cup of hot water. Steep covered 5 to 10 minutes for leaf or flowers, and 10 to 20 minutes for roots. Drink 2 to 4 cups/day. Tinctures may be used singly or in combination as noted.

• Coneflower (Echinacea purpurea): immunomodulating, increases phagocytosis; controversy exists whether to use for longer than two to six weeks at a time and whether to use in autoimmune conditions or AIDS.
• Goldenseal (Hydrastis canadensis): antiviral, antibacterial
• Astragalus (Astragalus membranaceus): increases interferon to shorten duration of colds
• Licorice (Glycyrrhiza glabra): antiviral, soothing to mucous membranes
• Elderberry (Sambucus nigra): antiviral, increases bronchial secretions

Use a mix of the above every two to four hours (1 cup tea or 30 to 60 drops tincture).

An experienced homeopath should assess individual constitutional types and severity of disease to select the correct remedy and potency. For acute prescribing use 3 to 5 pellets of a 12X to 30C remedy every one to four hours until acute symptoms resolve.

• Allium cepa for colds with profuse watery discharge that burns and/or irritates the nostrils
• Euphrasia for colds with profuse watery discharge that is irritating to the eyes
• Aconite for colds that come on suddenly, with fever and anxiety
• Mercurius for profuse discharge that is irritating everywhere; patient feels weak

Acupuncture for increased circulation, particularly helpful with Chinese herbal formulas.

Patients must learn that antibiotics cannot cure colds. High fever, sinus tenderness, purulent sputum, dyspnea, and chest pain are indications they should seek medical attention.

Children get colds more often than adults do. Day care centers and schools increase exposure to and frequency of illness.

Colds are transmitted by small aerosol particles, airborne droplets, or secretions transferred by hand with subsequent self-inoculation. Careful hand washing and avoiding contact with the eyes and nose is the best prevention for nonaerosol types of infection. Interferon intranasal sprays are moderately prophylactic (especially for rhinovirus) but may cause localized nasal irritation or damage (e.g., oxymetazoline 0.05%, two sprays to each nostril bid for five days). High doses of vitamin C and zinc lozenges may be no more effective in preventing a cold than placebo, depending on the study.

Secondary bacterial infections can cause complication in viral colds.

• Otitis media: in 5% of preschoolers
• Asthma and chronic pulmonary disease
• Sinusitis: in 0.5% of colds; suspect when cold persists 7 to 10 days past onset
• Bronchitis: more likely with coronavirus
• Pneumonia, bronchiolitis, diarrhea, and keratoconjunctivitis: more common with adenovirus

Colds usually last five to seven days in adults and 10 to 14 days in children. Without complications, they are benign and self-limiting.

Goldenseal is contraindicated in pregnancy because of its ability to stimulate oxytocin and uterine contractions. Alpha-adrenergic compounds and epinephrine (except in cases of anaphylaxis) should be avoided. Dextromethorphan should not be prescribed for cough. The most conservative treatment for colds in pregnancy is rest and fluids.

Behrman RE, ed. Nelson Textbook of Pediatrics. 15th ed. Philadelphia, Pa: WB Saunders Co; 1996.

Cummings S, Ullman D. Homeopathic Medicines. Los Angeles, Calif: Jeremy P. Tarcher, Inc; 1984.

Dorn M, Knick E, Lewith G. Placebo-controlled, double-blind study of Echinacea pallidae radix in upper respiratory tract infections. Complementary Therapies in Medicine. 1997;5:40-42.

Eby GA. Zinc ion availability—the determinant of efficacy in zinc lozenge treatment of common colds. J Antimicrob Chemother. 1997;40:483-493.

Fauci AS, Braunwald E, Isselbacher KJ, et al., eds. Harrison's Principles of Internal Medicine. 14th ed. New York, NY: McGraw-Hill; 1998.

Garland ML, Hagmeyer KO. The role of zinc lozenges in treatment of the common cold. Ann Pharmacother. 1998;32:63-69.

Gruenwald J, Brendler T, Jaenicke C, et al., eds. PDR for Herbal Medicines. Montvale, NJ: Medical Economics Co; 1998:817.

Hoheisel O, Sandberg M, Bertram S, Bulitta M, Schäfer M. Echinagard treatment shortens the course of the common cold: a double-blind, placebo-controlled clinical trial. Eur J Clin Res. 1997;9:261-269.

Melchart D, Walther E, Linde K, Brandmeier R, Lersch, C. Echinacea root extracts for the prevention of upper respiratory tract infections. Arch Fam Med. 1998;7:541-545.

Morrison R. Desktop Guide to Keynotes and Confirmatory Symptoms. Albany, Calif: Hahnemann Clinic Publishing; 1993:3-6, 13-14, 158, 244-246.

Sazawal S, Black RE, Jalla S, et al. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial. Pediatrics. 1998;102(part 1):1-5.

Scaglione, et al. Efficacy and safety of the standardized ginseng extract G115 for potentiating vaccination against common cold and/or influenza syndrome. Drugs Exp Clin Res. 1996;22:65-72.

Schöneberger D. The influence of immune-stimulating effects of pressed juice from Echinacea purpurea on the course and severity of colds. Forum Immunol. 1992;8:2-12.