Hot tub folliculitis, or pseudomonas folliculitis, is a skin infection that results from bacteria called Pseudomonas aeruginosa. The infection is usually the result of using poorly maintained hot tubs.

In this article, learn about the causes and symptoms of hot tub folliculitis, as well as what it looks like and how to treat it.

Causes

Hot tub jacuzzi outdoors
P. aeruginosa is a bacteria that can grow in hot tubs.

Hot tub folliculitis occurs when a person gets a P. aeruginosa infection.

The P. aeruginosa bacteria multiply in hot temperatures and thrive in the type of water conditions found in poorly maintained hot tubs. The bacteria can still survive in chlorinated water.

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It can also grow in other warm, wet places such as:

  • contaminated pools
  • lakes and rivers
  • water slides
  • whirlpools

Other research shows that nylon bath poufs or towels can harbor bacteria and cause pseudomonas folliculitis.

These bacteria enter hair follicles, causing itchy, red or purple bumps on the skin.

Hot tub folliculitis will often clear up without any treatment within a few days. The infection is usually harmless in otherwise healthy people.

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In this article, learn more about the symptoms of hot tub folliculitis, as well as about treatment and prevention.

Symptoms

The main symptom of hot tub folliculitis is a rash of itchy bumps on the skin. The rash may be red, purple, or inflamed, and the skin may feel tender.

These bumps can appear anywhere on the body but usually occur around the abdomen or any area covered by swimwear. This is because the swimwear keeps the infected water in contact with the skin for longer.

The bumps look similar to acne and may contain pus. People may also feel ill and experience fatigue or a high temperature.

A hot tub folliculitis rash and other symptoms can develop between 12–48 hours after using a hot tub.

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Diagnosis

A doctor will be able to diagnose hot tub folliculitis by examining the skin and asking a person about their medical history and any recent use of hot tubs or similar.

Hot tub folliculitis can look similar to other skin conditions, including:

  • acne
  • psoriasis
  • other types of folliculitis
  • other types of bacterial infection, such as a staph infection
  • chemical rashes

To prevent a misdiagnosis, a doctor may take a sample of the skin with a swab. They will send this sample to a laboratory for examination under a microscope. A professional in the lab can confirm whether the condition is hot tub folliculitis or another condition.

Treatment

Hot tub folliculitis will often clear up by itself within 5–10 days. If the rash lasts longer than this, or people are experiencing other symptoms, it is best to speak to a doctor.

People should also see their doctor if they have an existing condition that affects their immune system, or if they have cystic fibrosis. The bacteria P. aeruginosa can cause pneumonia in people who have cystic fibrosis.

A doctor may prescribe a topical medication, such as silver sulfadiazine cream, to treat hot tub folliculitis. People can apply this twice a day, or as instructed by their doctor.

The American Osteopathic College of Dermatology recommend that people can apply white vinegar to treat hot tub folliculitis. People can apply white vinegar to the infected area for 20 minutes at a time, repeating between two to four times a day.

When applying a topical medication, people should apply the solution in the same direction as any hair growth. People should also leave the area uncovered from any bandages or dressings. This can help to reduce folliculitis.

People should also avoid shaving or scratching the area where the folliculitis rash is, as this can irritate the skin.

If topical medication does not treat hot tub folliculitis effectively, a doctor may prescribe oral antibiotics.

People can apply a warm compress to the rash, which can soothe itchiness or pain and help to clear the condition more quickly. The American Academy of Dermatology advise using a warm compress for 15–20 minutes, three to four times a day, or as many times as a person needs to relieve pain.

Once the rash has cleared, it may leave hyperpigmented marks on the skin. These may be red to brown and may take a few months to disappear.

Prevention

Bikini swimwear drying on clothing lines outdoors
Drying swimwear before wearing it again can help prevent hot tub folliculitis.

People can take steps to prevent hot tub folliculitis, such as:

  • removing swimwear soon after getting out the hot tub and putting it in the wash
  • showering with hot water and soap straight after using a hot tub
  • making sure swimwear is completely dry before wearing it again
  • checking that a public hot tub operator is servicing the hot tub at least twice a day

People should take extra care or avoid hot tub use if they have:

  • areas of broken skin or open wounds that are prone to infection
  • a condition that affects their immune system
  • cystic fibrosis

If people are using their own hot tub, they can keep it clean and safe by:

  • using test strips to check pH and disinfectant levels
  • replacing the hot tub water regularly
  • thoroughly cleaning and scrub all parts of the pool regularly
  • following manual instructions for replacing the water filter

People can purchase hot tub test strips online or from hardware and pool supply stores.

The Centers for Disease Control and Prevention (CDC) recommend the following levels for hot tubs:

  • Free chlorine: 2–4 parts per million (ppm)
  • Bromine: 4–6ppm
  • pH: 7.2–7.8

To prevent getting hot tub folliculitis from bath sponges, soak them in a gallon of water with ¾ cup of chlorine bleach for at least 5 minutes to kill any bacteria. Remove them and rinse them thoroughly before use.

Summary

Hot tub folliculitis is a bacterial skin infection that people can pick up from poorly maintained hot tubs. It causes itchy, red bumps on the skin, particularly in areas that are underneath swimwear.

People will usually find that the infection clears within a few days without any treatment.

If the condition does not resolve itself within 10 days, it is best to see a doctor. Treatment may include topical medication or taking oral antibiotics.