When you're in a hot tub that hasn't been properly maintained, a germ called "Pseudomonas aeruginosa" can creep into hair follicles and lead to a rash, explains Meghan Feely, MD, FAAD a board-certified dermatologist and clinical instructor at Mount Sinai’s Department of Dermatology. Technically you can contract this from any body of water that you're in for a long period of time, such as pools, water parks, or lakes, she adds. But since hot tubs have warmer water, chlorine breaks down faster, meaning bacteria can really thrive, according to the Centers for Disease Control (CDC). Hence why it's often associated with hot tub use.The telltale sign of hot tub folliculitis is red bumps that resemble acne around your bathing suit area, Dr. Feely says. These spots usually appear a 12-48 hours after you've been in a hot tub, and they may itch or become pus-y over time, according to the American Academy of Dermatology (AAD).AdvertisementIt's a good idea to see a board-certified dermatologist who can diagnose the condition or rule out anything more serious, Dr. Feely says. They might prescribe a topical treatment, such as silver sulfadiazine cream, she says. (In some cases, you might also need to take an oral antibiotic to systemically treat the infection, she says.) "Your dermatologist will also advise taking a break from shaving in active areas of folliculitis, as this will cause irritation," she says. Using a warm compresses on the rash can help to ease some of the discomfort or itch, she adds.Most of the time, the rash will go away on its own after a few days, according to the CDC. But if it lingers any longer than that, you should definitely get to a doctor.