Hot Tub Folliculitis – Causes, Symptoms, Treatment and Prevention

What is Hot Tub Folliculitis?

Hot tub (spa pool) folliculitis is an infection of the hair follicles caused by a bacterium Pseudomonas aeruginosa. It often thrives in poorly chlorinated warm water housed in wooden vessels as is the case with hot tubs, whirlpools or jacuzzis.  Folliculitis is not an uncommon superficial infection and most cases are due to bacteria. This is where the follicles, at the base of the hair shaft, becomes infected.

Causes of Hot Tub Folliculitis

While a number of different bacteria can cause folliculitis, Pseudomonas aeruginosa is the main cause of hot tub folliculitis. Therefore is also referred to as Pseudomnonas folliculitis. As mentioned, hot tubs and jacuzzis are the main source of these bacteria in this type of folliculitis. It is able to thrive in the water because it is warm and usually not chlorinated.

However, there are cases where this bacteria may be thriving in heat swimming pools, particularly if these pools are not properly chlorinated and maintained. It can alo be found on the surface and in the drainage system of chlorinated water pools but usually in much smaller quantities. Similarly Pseudomonas folliculitis can also be spread by using water slides and sharing bath tub water.

The presence of organic material in the water, such as human skin cells, also increases the chance of Pseudomonas aeruginosa thriving in the water. A thin biofilm shields the bacteria on the surface of the tub or other similar surfaces. Without thorough cleaning, the bacteria will not be removed and can remain on the surfaces for prolonged periods of time until it is released into the water.

Hot tub - spa pool

Symptoms of Hot Tub Folliculitis

Within eight hours to five days (or even 14 days) of exposure to the bacteria, red, itchy bumps appear on the skin and may later develop into small pus-filled blisters (pustules). The rash is likely to be worse in areas where a swimsuit holds contaminated water against the skin. Therefore the face and neck are rarely involved. The palms and soles are never affected (1).

Rarely, an earache, sore throat or eyes, runny nose, headache, nausea, vomiting, mild fever, breast tenderness, or painful lymph nodes may appear (1). Red wheals up to 3 cm wide may occasionally encircle the bumps (2). The presence of large blisters (abscesses) needs to be investigated and treated immediately. Depending on the severity of the infection, individual immune health and treatment, the infection can persist for days to weeks.

Risk Factors for Hot Tub Folliculitis

Overall Pseudomonas folliculitis is not as common as folliculitis due to other bacteria and methods of spread. It is more likely to occur in persons with:

  • Prolonged water exposure.
  • Many bathers in one hot tubs.
  • Frequent use of hot tubs.
  • Spending long hours in water that is warm and poorly chlorinated.

Although a person with a healthy immune system can be just as much at risk of developing this type of folliculitis, people with a weakened immune system (like with HIV/AIDS or poorly controlled diabetes mellitus) need to be extra cautious, as is the case with any infection. Never go into a hot tub with an open wound, even if the wound is covered with surgical bandaging. People who have just undergone surgey need to be particularly careful in this regard.

Diagnosis of Pseudomonas Folliculitis

In diagnosis, a personal medical history may help a lot. A history of using hot tub in 2 days before a rash eruption, and other members of the party using the same hot tub and getting the same rash both speak for Pseudomonas folliculitis. A doctor may usually give diagnosis on the basis of physical examination, and further tests are not needed. In doubtful cases, a swab from open pustules can be taken and sent to a microbiology laboratory. Pseudomonas folliculitis, without knowing a history, may be hard to differ from staphylococcal folliculitis (pictures of Staphyloccocal folliculitis).

Treatment of Hot Tub Folliculitis

Mild cases do not require treatment and resolve in 2 to 10 days (1). There is no evidence that mild pseudomonas folliculitis responds to antibiotics as the infection is superficial. However, antimicrobial creams may be useful in restricting the spread of the infection and help with resolution(1).

Compresses with 5% acetic acid (white vinegar), 2 to 4 times a day for 20 minutes may bring some relief.  Extensive or repeated spa pool folliculitis can be treated with oral ciprofloxacin (1). The pool should be properly cleaned and disinfected with adequate chlorination or other method.

Complications of Hot Tub Folliculitis

Complications with hot tub folliculitis are uncomon. However, complications are more likely to arise in the event of repeated infections, open wounds and a weakened immune system. Pseudomonas folliculitis rash may leave hyperpigmented spots (darkened skin) for few months after the rash disappears (2). Although uncommon, the infection could extend deeper under certain circumstances thereby causing a much more serious infection. This is more likely to happen with scratching and an open wound that allows other microbes to enter into deeper tissue.

Prevention of Hot Tub Folliculitis

The following measures can help in preventing Pseudomonas skin infections:

  • Chlorination with maintaining 2mg/L of free chlorine (bromine can be even a better choice), (1)
  • Complete drying of sponges between baths and replacing these sponges on a regular basis.
  • Empty out bath water after bathing and refill with clean water for the next person to use.

Showering after using hot tubs does not seem to prevent Pseudomonas folliculitis (1). Nevertheless bathing afterwards especially with an antibacterial soap may be helpful. Pseudomonas folliculitis is not spread by skin to skin contact (2). Therefore one person cannot get it when making direct contact with another person who has the infection.

How to Treat Hot Tubs?

Refer to these articles from the CDC about healthy swimming for more information on how to disinfect hot tubs and maintain it in conditions that is less likely to contribute to hot tub folliculitis and other infectious disease. Proper maintenance and regular cleaning can greatly reduce the risk of contracting these infections.

Related Articles:


  1. Hot tub folliculitis (
  2. Hyperpigmentation in pseudomonas folliculits (
About Jan Modric (209 Articles)
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