In September of 2000, a physician in northern California noticed that four of her patients had the same severe, scarring boils on their lower legs—and that all four had gotten pedicures at the same nail salon! The boils were the result of infection caused by mycobacteria. The physician reported these cases to the local health department, launching an investigation into sanitary conditions at the salon and 110 salon patrons who contracted the same infection.
A recent article in
The New England Journal of Medicine
details how researchers determined that whirlpool footbaths harbored the mycobacteria and identified factors that caused some patrons to become infected but not others.
About the study
Health officials in northern California notified all local primary care physicians and dermatologists of the suspicious infections and asked that they report any skin infections of the lower legs among patients who had pedicures at the particular salon. Researchers from the Centers for Disease Control and Prevention, along with California health officials, launched an investigation of people who had pedicures at the salon between April and October of 2000.
The researchers enrolled the first 48 patients with boils (cases) that tested negative for routine bacterial infection or did not respond to antibiotic therapy. (Note: Mycobacteria are not usually among the bacteria routinely tested for in cases of skin infection.) Because certain forms of mycobacteria are known to cause skin infections, the researchers tested the patients’ boils for mycobacteria. In addition, 56 friends and family members who had pedicures at the salon but did not develop boils were enrolled as controls.
All participants completed a structured questionnaire that included details of their last pedicure, such as the footbath, leg massage (with or without oil or lotion), and whether they had shaved their legs before the pedicure.
In addition, health officials examined the salon, the whirlpool footbaths, and all substances that came in contact with the patrons’ legs (oils, lotions, soaps, cleansers, etc.). They also took samples of these substances to be tested for mycobacteria and compared them with the mycobacteria found in samples taken from the patrons’ boils. Finally, they compared the occurrence of leg massage and recent leg shaving among cases and controls.
All 10 of the salon’s footbaths tested positive for mycobacteria, as did the tap water. Large amounts of hair and skin debris were found behind the inlet suction screens of the footbaths and the salon owner reported that areas behind the screens were never cleaned. In particular, one type of mycobacteria in the footbaths matched the mycobacteria cultured from some of the patrons’ boils. However, several types of mycobacteria were present both behind the footbath screens and in patrons’ boils.
Women who had shaved their legs prior to the pedicure (that morning or the night before) were nearly 5 times more likely to have developed boils than women who had not shaved recently.
The good news was that oral antibiotics known to treat mycobacterial infections successfully treated the boils in all 48 patients.
Although these results are interesting (and a little alarming), there are limitations to this study. The study was conducted in a single nail salon, so these findings may not apply to other nail salons. In addition, only the participants’ exposures at the nail salon were rigorously examined. Any other factors that may have contributed to the development of their infections, such as hygiene habits, were not examined.
How does this affect you?
Should you skip the footbath portion of your pedicure from now on? Not necessarily. This study was conducted in only one nail salon, and other salons may be more rigorous in cleaning their footbaths. However, you should be aware that footbaths can harbor infectious organisms. Although the presence of some mycobacteria in tap water is common, researchers suspect that in this case the small amount of mycobacteria in the tap water collected behind the screens in the footbaths. This provided debris for them to feed on and a warm, wet environment to multiply and then begin circulating around the footbaths.
What can you do to protect yourself from infection when you have a pedicure?
First, you could skip the whirlpool footbath entirely.
Second, these findings suggest that
shaving your legs the night before or the day of your pedicure may reduce your risk of contracting an infection from any organisms that may be present in the footbath.
Third, ask your nail salon how often they clean behind the inlet suction screens. If you’re not satisfied with their answer, find another salon that does clean behind these screens. And if you’re up to it, you can even ask to see behind the screens.
Finally, check with your local health department about how sanitary conditions at nails salons in your area are regulated and advocate for stronger regulations, if necessary. As a result of this outbreak and this study, the California Bureau of Barbering and Cosmetology has proposed new state regulations for the nail-care industry that include frequent cleaning behind the inlet suction screens of footbaths. However, further study is needed to determine optimal disinfection procedures.
Winthrop FL, et al. An outbreak of mycobacterial furunculosis associated with footbaths at a nail salon.
New England Journal of Medicine
. May 2, 2002;346(18):1366-1371.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a