A 50-year-old woman presents with acute onset of an itchy eruption on her upper back and arm following a weekend spent hiking and relaxing at a day spa. As a child she experienced numerous bouts of poison ivy but has had no similar cases for most of her adult life. The patient has been taking lovastatin for the past 18 months.
Can you diagnose this condition?
Submit your diagnosis to see full explanation.
Hot tub folliculitis, also known as Pseudomonas folliculitis, is the result of Pseudomonas colonization of hair follicles. Pseudomonas aeruginosa is a contaminant of contained water sources such as whirlpools, swimming pools, and hot tubs.1,2 The rash associated with Pseudomonas folliculitis typically develops within 48 hours of water exposure but may take up to 14 days to appear.3
Patients present with itchy, erythematous macules that progress into papules and pustules. The rash can develop in any area exposed to water and may be most prominent on those sites that are in direct contact with a swimsuit. Hot tub folliculitis is a self-limiting condition that usually resolves within 10 days. Oral antibiotics are ineffectual and not warranted. Preventive measures include thorough cleaning of hot tubs and spas and maintaining proper concentrations of chlorine and bromine.4,5
Stephen Schleicher, MD, is director of the DermDox Center for Dermatology, as well as an associate professor of medicine at Commonwealth Medical College and a clinical instructor of dermatology at Arcadia University and Kings College.
1. Gregory DW, Schaffner W. Pseudomonas infections associated with hot tubs and other environments. Infect Dis Clin North Am. 1987;1(3):635-648.
2. Price D, Ahearn DG. Incidence and persistence of Pseudomonas aeruginosa in whirlpools. J Clin Microbiol. 1988;26(9):1650-1654.
3. Berger RS, Seifert MR. Whirlpool folliculitis: a review of its cause, treatment, and prevention. Cutis. 1990;45(2):97-98.
4. Centers for Disease Control and Prevention. Suggested health and safety guidelines for public spas and hot tubs. https://www.cdc.gov/healthywater/pdf/swimming/pools/public-spas-and-hot-tubs-1985.pdf. Updated January 1985. Accessed October 3, 2019.
5. Hlavsa MC, Cikesh BL, Roberts VA, et al. Outbreaks associated with treated recreational water — United States, 2000–2014.MMWR Morb Mortal Wkly Rep. 2018;67(19):547-551.