The color of mucus

As one person commented on a previous blog, it can be tricky to distinguish colds from flu. In reviewing an article on just that topic, I was surprised to read that the color of mucus (aka nasal discharge, sputum, plegm, snot) did not accurately reflect whether an infection was viral or bacterial. I, like many herbalists, was taught that nasal discharge turning from clear to yellow or green shades indicated that a bacterial infection was settling in. It turns out that doctors also share this view. They are most likely to prescribe antibiotics in patients who have a cough and colored nasal discharge. In fact, one study found that patients were seven more times to be prescribed antibiotics if their nasal discharge was “discolored.”

Bad idea, said the article as they may be dispensing antibiotics for viral infections, an unnecessary and inappropriate use of antibiotics. “[T]he appearance of these secretions alone is not predictive of bacterial infection or the effectiveness of antimicrobial therapy.” Overall, the view is that changes in mucus to yellow, thick, or green occur naturally in the course of viral respiratory infection and do not support the use of antibiotics. Antibiotics are only appropriate where there is a persistent daytime cough or rhinorrhea lasting more than 10-14 days or there are severe symptoms of acute sinus infection (fever with purulent nasal discharge).

Herbalists tend to begin prescribing goldenseal (Hydrastis canadensis) when the color of the mucus changes, often explaining that this shows that the infection is now bacterial. Perhaps, however, what we are really doing is using an excellent mucus membrane tonic to reduce inflammation rather than using the herb as an antibacterial. Paul Bergner suggests this is the appropriate use of goldenseal in one of his excellent articles: “It is my opinion that goldenseal acts as an “antibiotic” to the mucous membranes not by killing germs directly, but by increasing the flow of healthy mucous, which contains it’s own innate antibiotic factors — IgA antibodies. This effect is unnecessary in the early stages of a cold or flu, when mucous is already flowing freely.”

That said, even Paul shares the hard to shake view that the color of the discharge indicates the nature of the infection: “a client with a chronic dry bronchitis had been coughing up only slight amounts of clear phlegm for several weeks. Then the discharges turned to yellow and green — a sign of the onset of bacterial infection and the threat of pneumonia.” What we should be saying is that the change in the color of the discharges indicates inflamed mucus membranes in need of a mucus membrane tonic (goldenseal being one of, if not the best) to prevent a condition from developing that will favor a secondary bacterial infection from taking hold.

Paul Bergner on goldenseal:

Mainous, AG III, Hueson WJ, Eberlein C. Color of respiratory discharge and antibiotic use. Lancet 1997; 350:1077-1079.

Eccles. Understanding the symptoms of the common cold and influenza. Lancet 2005; 5:718-725.

Careful antibiotic use.

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