What is Hot Tub Folliculitis?
Hot tub (spa pool) folliculitis is infection of hair follicles caused by bacterium Pseudomonas aeruginosa which often thrives in new, poorly chlorinated, especially wooden hot tubes or whirlpools (Picture 1).

Picture 1. Hot tub
Symptoms of Hot Tub Folliculitis
Within eight hours to five days (or even 14 days) of exposure to the bacteria, red, itchy bumps appear that later may develop into small pus-filled blisters (pustules). The rash is likely to be worse in areas where swimsuit holds contaminated water against the skin; face and neck are rarely, and palms and soles are never affected (1). Rarely 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 (Picture 2), (2).
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Picture 2. Hot tub folliculitis.
Click to enlarge >> © Dermnet.com
More Pictures of Hot Tub Folliculitis
Risk Factors for Hot Tub Folliculitis
Pseudomonas folliculitis is more likely to occur in persons with:
- prolonged water exposure
- many bathers in one hot tub
- frequent use of hot tubes (1)
Diagnosis of Pseudomonas Folliculitis
In diagnosis history may help a lot. History of using hot tub in 2 days before rash eruption, and other members of the party using the same hot tub and getting the same rash both speak for Pseudomonas folliculitis. 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 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 2-10 days (1). There’s no evidence that mild pseudomonas responds to antibiotics (1). Compresses with 5% acetic acid (white vinegar), 2-4 times a day for 20 minutes may bring some symptoms relief. Extensive or repeated spa pool folliculitis can be treated with oral ciprofloxacin (1).
The responsible pool should be properly cleaned and disinfected with adequate chlorination or other method.
Complications of Hot Tub Folliculitis
Pseudomonas folliculitis rash may leave hyperpigmented spots for few months after rash dissapearing (2).
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
- or simply avoiding hot tubs
Showering after hot tubs use does not seem to prevent pseudomonas folliculitis (1). Pseudomonas folliculitis is not spread by skin to skin contact (2).
How to treat Hot Tubs?
Here are some information about how to treat spa pools, and here’s more info from CDC about healthy swimming.
References:
- http://www.emedicine.com/DERM/topic356.htm SYMPTOMS, DIAGNOSIS, RISK FACTORS, TREATMENT AND PREVENTION OF HOT TUB FOLLICULITIS
- http://dermatology.about.com/od/infectionbacteria/a/htfolliculitis.htm PSEUDOMONAS FOLLICULITIS - HYPERPIGMENTATION


Hello, Any ideas on where we could go to learn more regarding just how this is spread through the water? Is this just a bacteria not being killed by some chemical programs - or a strain resistant to all??
Scott Jacob