Hot tub folliculitis is an itchy, red, bumpy rash that occurs within 1-4 days of bathing in a hot tub, whirlpool, or public swimming pool. As water temperature rises, changes occur in the amount of free chlorine.
This alters the ability of the chlorine to kill bacteria, and the bacteria then grow. The most commonly associated bacteria is Pseudomonas aeruginosa. The bacteria infect the hair follicles and cause red bumps and pus or pimple like bumps to develop.
Areas that are typically affected include the sides of the torso, armpits, buttocks, arms, thighs and breasts. Earaches, sore throat, headache, fever and malaise have been associated with the rash. Rarely, the infection can spread to the blood.
The rash tends to go away on its own without treatment in 7-14 days, but sometimes antibiotics may be applied to the skin or taken by mouth to hasten resolution of the rash. Preventative measures include water filtration, automatic chlorination to maintain free chlorine at 1 ppm, maintaining water pH between 7.2 and 7.8, and changing water.
James WD, Berger TG, Elson DM. Andrews’ diseases of the skin: clinical dermatology, 10th edition. Saunders, 2005.
Angela Leo, D.O.
Department of Dermatology
Philadelphia College of Osteopathic Medicine/Frankford Hospital