"Hot Tub Rash" Outbreak
A Rash of Hot Tub Rashes
The winter weeks following February 7, 1999 were itchy ones for some 34 people who contracted "hot tub rash" or Pseudomonas dermatitis through contact with contaminated water. The outbreak was initially noticed when the Colorado Department of Public Health and Environment (CDPHE) was notified of 15 people with a rash following use of a hotel pool and hot tub.1 An additional 25 community residents who used the hotel's pool and hot tub on a pay-to-swim basis were identified and of the 20 people who used the hot tub, 19 developed "hot tub rash”. The rashes occurred among children and adults attending two birthday parties at the hotel and among community residents who used the pool on a pay-to-swim basis.
Skin infections are the most common infections spread through hot tubs and spas and usually occur as a result of low disinfectant levels that allow contaminating germs, like the bacterium Pseudomonas, to multiply. The hot tub at the Colorado hotel relied on an automated chlorination and pH adjustment system. A printout of the hourly free chlorine and pH levels in the pool and hot tub revealed that chlorine levels dropped below 1 ppm on the evening of February 4th due to a faulty chlorine pellet dispenser. Because hotel staff did not perform routine onsite water testing for the pool or hot tub and did not check monitor readings, the disinfectant levels remained below 1 ppm for almost 3 days.
Several factors contributed to the outbreak of "hot tub rash" including: hotel employees with a minimal understanding of the equipment, no regular checking of the disinfection equipment, poor pool and spa maintenance, and a lack of awareness of the link between water disinfection and disease transmission by staff. To reduce the risk for outbreaks of "hot tub rash," pool and hot tub operators should:
- Follow regulatory requirements for pH and disinfectant levels in hot tubs.
- Ensure all staff members have a thorough knowledge of basic aquatic facility operation.
- Monitor hot tub disinfectant levels on an hourly basis.
- Perform regular checks of automated equipment to ensure that it is working properly.
While automated systems may save time, they are not foolproof. They should not take the place of periodic, manual testing of disinfectant and pH. Following these guidelines will help to prevent the spread of dermatitis and give hot tub patrons a "rash-free" season.
For additional spa operation guidelines visit: http://www.cdc.gov/healthyswimming/pdf/spa_operation.pdf 
(PDF, 961 KB)
- Pseudomonas dermatitis/folliculitis associated with pools and hot tubs---Colorado and Maine, 1999-2000. (2000) MMWR Morb Mortal Wkly Rep 49:1087-1091.
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Page last modified: May 2, 2007