Hot tub folliculitis

Folliculitis is a superficial infection of the hair follicle. Hot tub folliculitis is an infection that develops after exposure to certain forms of bacteria that reside in warm, wet environments such as hot tubs.

Causes, incidence, and risk factors

Most folliculitis is caused by the common organism Staphylococcus aureus. However, hot tub folliculitis is caused by Pseudomonas aeruginosa. Pseudomonas survives in hot tubs, especially hot tubs made of wood, unless the pH and chlorine content are strictly controlled.

Hot tub folliculitis becomes noticeable within several hours to 2 days of exposure. It first appears as itchy bumps, some of which may be filled with pus. It may then develop into dark red tender nodules. The rash may be more dense under swimsuit areas, where the material has held the contaminated water in contact with the skin for a longer period of time.


  • History of using hot tub within previous 3 days  
  • Itchy, bumpy, red rash appearing within 2 days of hot tub exposure  
  • Bumps developing into dark red tender nodules  
  • Bumps developing small pustules (pus-filled blisters)  
  • Multiple members of family or party with same rash and same hot tub exposure

Signs and tests
Physical examination combined with a history of recent hot tub use are sufficient for your health care provider to make this diagnosis. Testing is usually unnecessary.


Treatment may not be needed, as the mild form of the disease usually clears on its own. Oral or topical anti-pruritics (anti-itch medications) may be used.

In severe cases, your physician may prescribe an oral antibiotic such as ciprofloxacin.

Expectations (prognosis)

This condition usually clears without scarring. It may recur if the infected hot tub is not cleaned.


  • Abscess formation (rare)  
  • Discomfort

Calling your health care provider
Call your health care provider if you develop symptoms of hot tub folliculitis.

Careful attention to controlling the pH and chlorine content of the hot tub may help to prevent hot tub folliculitis.

Johns Hopkins patient information

Last revised: December 3, 2012
by Levon Ter-Markosyan, D.M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.