Hot tubs may be great for sociability and mental health, but that doesn't give them a clean bill of health.
A newly recognized threat to hot-tub happiness is something called "whirlpool folliculitis," warns Dr. Richard Berger, a dermatologist at the University of Medicine and Dentistry of New Jersey in New Brunswick.The infection is caused by bacteria that are drawn to moist soil and water and seem to be particularly fond of the skin around hair follicles. They also cause swimmer's ear.
The bug is almost impossible to wipe out in whirlpools and other public baths, where it gets everything it could want: moisture, warmth and plenty of human bodies.
A few days after exposure, bathers develop a rash characterized by small red blisters or bumps resembling insect bites.
The bad news is that the bacteria resist virtually all treatment. The good news is that they usually disappear on their own after a week or so. They don't scar, and they rarely come back - until the next session in a hot tub.
For the tubs, cleanliness is close to godliness for this health threat.