Hot Tub and Pool Folliculitis

Who doesn’t love a swimming pool or hot tub? They practically equate to fun and relaxation! Well… unless you are an Emergency Medicine clinician… in which case you naturally see hazards everywhere (it is one of our super powers). While the obvious hazards, like Submersion Related Injuries (ex, C-Spine, Prolonged QTc) are critically important for everyone to be alert to (ie, Prevention), there are other less critical water-related problems that may cause patients to seek care. Dr. Tyler Constantine reminded me of one of these that does deserve a quick comment (even though I hate Rashes). Let us review Hot Tub and Pool Folliculitis:

Hot Tub and Pool Folliculitis: Pseudomonas Folliculitis

  • Pseudomonas aeruginosa:
    • Gram – negative rod pathogen
    • Is ubiquitous, especially in water systems. [Lutz, 2011]
    • Have numerous mechanisms affording it antibiotic resistance.
      • Low outer membrane permeability
      • Efflux pumps
      • Additional mutations that increase antibiotic resistance
    • Globally, ~ 10% are found to have MULTI-drug resistance.
      • 96% of isolates from pools and hot tubs were found to be resistant to MULTIPLE antibiotics!! [Lutz, 2011]
  • Pseudomonas aeruginosa thrives in recreational water (ie, Hot Tubs and Pools). [Lutz, 2011]
    • It grows well in water that is 39-107 degrees Fahrenheit (4-42 degrees Celsius)
    • The complex, inaccessible piping systems of hot tubs and pools make eradication of P. aeruginosa difficult even when they are cleaned appropriately per guidelines.
    • High temperatures and agitation (Hot Tub jets) can reduce efficacy of disinfectants as well. [Lutz, 2011]
    • Despite guidelines, residential recreational water may not cleaned and maintained up to standards.
  • Pseudomonas aeruginosa also thrive in occlusive swimming attire. [Lutz, 2011]
    • Especially when kept in prolonged contact with wet skin.
    • After swimming/bathing the CDC recommends to:
      • Remove swimsuits
      • Shower
      • Clean swimsuits
      • (So don’t just lounge all day in that petri dish you call a bathing suit!)

Hot Tub and Pool Folliculitis: Presentation

  • P. aeruginosa is an important cause Folliculitis and Otitis Externa associated with hot tubs and swimming pools. [Zacherle, 1982]
    • Cases documented since 1975.
    • Can cause isolated cases or epidemics. [Yu, 2007; MMWR, 2001; Ratnam, 1986]
  • Folliculitis presents as: [Zacherle, 1982]
    • Papules and some vesicles on a red base.
    • Some pustules may appear as well.
    • Often described as pruritic (but not always).
    • Typically spare the face, neck, mucous membranes, and palms/soles.
  • Incubation period = 6 hours – 48 hours (although can be up to 5 days) [Yu, 2007; Zacherle, 1982]
  • Can have concurrent systemic symptoms:
    • Myalgias and weakness
    • Chills and fevers
    • Headache
    • Sore throat
    • Earaches
    • Enlarged axillary lymphnodes

Hot Tub Folliculitis: Management

  • While this is related to a significant pathogen, it is typically a self-limited condition. [Zacherle, 1982]
  • In an immunocompetent host, no antibiotic therapy is required initially.
  • Some cases will have recurrence.
    • Obtaining cultures of lesions / vesicular fluid will be helpful in directing therapy.
    • Gram stain is also warranted.
  • Main management strategy is prevention:
    • CDC recommends regular testing of pools and hot tubs.
    • Bathing with soap after swimming/bathing is also important. [Zacherle, 1982]

Moral of the Morsel

  • Hot Tubs and Swimming Pools are petri dishes! If you see a rash, ask about exposure to the Hot Tubs and Swimming Pools.
  • Swim suits are petri dishes too! Give the families some helpful anticipatory guidance… don’t linger in that wet bathing suit!
  • Don’t throw antibiotics at it! Assess patient risk. If they are healthy, the condition will likely be self-limited and your antibiotic selection will likely only worsen antibiotic resistance patterns.
  • If you aren’t healthy, don’t sit in a petri dish! Gently remind families of this when they have a loved one who is immunocompromised!


Lutz JK1, Lee J. Prevalence and antimicrobial-resistance of Pseudomonas aeruginosa in swimming pools and hot tubs. Int J Environ Res Public Health. 2011 Feb;8(2):554-64. PMID: 21556203. [PubMed] [Read by QxMD]
Segna KG1, Koch LH, Williams JV. “Hot tub” Folliculitis from a nonchlorinated children’s pool. Pediatr Dermatol. 2011 Sep-Oct;28(5):590-1. PMID: 21453304. [PubMed] [Read by QxMD]
Yu Y1, Cheng AS, Wang L, Dunne WM, Bayliss SJ. Hot tub folliculitis or hot hand-foot syndrome caused by Pseudomonas aeruginosa. J Am Acad Dermatol. 2007 Oct;57(4):596-600. PMID: 17658195. [PubMed] [Read by QxMD]
Berger RS1, Seifert MR. Whirlpool folliculitis: a review of its cause, treatment, and prevention. Cutis. 1990 Feb;45(2):97-8. PMID: 2107063. [PubMed] [Read by QxMD]
Gregory DW1, Schaffner W. Pseudomonas infections associated with hot tubs and other environments. Infect Dis Clin North Am. 1987 Sep;1(3):635-48. PMID: 3504439. [PubMed] [Read by QxMD]
Ratnam S, Hogan K, March SB, Butler RW. Whirlpool-associated folliculitis caused by Pseudomonas aeruginosa: report of an outbreak and review. J Clin Microbiol. 1986 Mar;23(3):655-9. PMID: 3082930. [PubMed] [Read by QxMD]
Zacherle BJ, Silver DS. Hot tub folliculitis: a clinical syndrome. West J Med. 1982 Sep;137(3):191-4. PMID: 7147933. [PubMed] [Read by QxMD]


Sean M. Fox
Sean M. Fox
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