I recently had a patient with Pseudomonas aeruginosa or “hot tub” folliculitis, a bacterial infection of the hair follicles that occur after being in a contaminated pool (or hot tub or whirlpool). It’s a superficial infection that appears as round, red pustules. These pustules tend to be more severe in areas that have been covered by a bathing suit because the bathing suit traps the contaminated water against the skin. Showering after exposure does not minimize the chance of developing folliculitis.

The rash generally appears anywhere from 8 hours to 5 days after exposure. Although itchy and angry looking, it resolves spontaneously in 7-10 days. In symptomatic patients, an antibiotic can be prescribed but treatment is not generally required. Topical treatment includes a wet dressing of acetic acid (white vinegar) for 20 minutes 2-4 times a day.

Pseudomonas aeruginosa is a Gram-negative rod that grows rapidly in moist environments. It is a very common bacteria that is tolerant of a wide variety of environmental factors including antibiotics and even weak antiseptics. Since hot tubs can quickly breakdown chlorine and other disinfectants, it’s important to make sure that the proper pH is maintained, that the water is treated regularly with cholorine or bromine and that the water is changed in private hot tubs every 4-8 weeks.

For more information follow the link to the Centers for Disease Control (CDC).  More pictures of “hot tub” folliculitis are available here.