Spa & Hot Tub Skin Rashes

"My husband (or wife, child, friend) is allergic to the chlorine I use in my spa." That is a common comment made by many spa and hot tub owners who may not be thoroughly and properly caring for it. The thing is, itching and skin rashes are almost 99.99% preventable. The bacteria causing the itching and rash is named "Pseudomonas Aeruginosa," a very common occurring bacteria found in water and soil.

"Pseudomonas Aeruginosa," (PA) is also a very opportunistic bacteria. PA can cause:

  • Urinary Tract Infections
  • Dermatitis (Skin Rash or Pseudomonas Folliculitis)
  • Respiratory System Infections – sometimes known as "hot tub lung"
  • Swimmer's Ear (Otitis Externa) – please see your local doctor for treatment
  • Other systemic infections

In Spas & Hot tubs, a very likely cause of skin rash is Pseudomonas aeruginosa (PA). Pseudomonas feeds on oil & grease present in the spa water (mainly from body oils & skin treatments brought into the spa from bathers not properly showering prior to entering the spa or hot tub) and can multiply rapidly under ideal conditions (such as lack of proper sanitizing procedures). In swimming pools, PA can be found on various areas such as pool coping, waterfall stairs, ladder steps, etc. PA infects the hair follicles on the body. If infected, you will notice the following characteristics of Pseudomonas Aeruginosa:

  • Itchy rash 8 to 48 hours after contamination.
  • Rash can occur on arms, legs or trunk of body.
  • Rash disappoints 7 to 10 days without treatment.

The first question we ask customers is "where" the rash is. Because PA likes to live and multiply in water, the "best" place for this is on any surface of the spa or hot tub, but particularly along and at the waterline. Customers usually tell us that the rash is across the back or under the arms or the back of the legs or a combination of all of these areas. Depending on how bad the "infestation" of the Pseudomonas bacteria and the burden of sensitivity will determine how bad the outbreak will be. PLEASE CONSULT YOUR PHYSICIAN IF A SERIOUS RASH OCCURS.

Remember that the best thing is to prevent these rashes from ever occurring in the first place. Although water chemistry and proper use of sanitizers is important, regular cleaning and maintenance is equally important. Regular cleaning means something as simple as wiping down all of the spa's surfaces with your hand or a cloth every time you go in. I know that sounds crazy (drives my wife a little nuts actually – but no skin rashes in over 20 years of spa ownership). Wiping down aids in cleaning and circulation. Simply putting properly sanitized and treated water on the top edge of the spa where the cover has sat (creating its own bio-film) will aid in killing unwanted bacteria that may cause a skin rash on the underside of your arms as you sit in the spa with your arms outside, resting on the edge.

If you suspect that your spa or hot tub is infected with pseudomonas aeruginosa, perform the following cleaning steps:

  1. Drain the spa.
  2. Remove the filter and soak in a solution of chlorine and water during treatment. (2 Tbsp of granular sodium dichlor Chlorine per 5 gallons of water)
  3. Clean all spa surfaces that may come in contact with a bather's skin (especially especially arm pits, chest & back) – above & below the waterline. Be sure the chlorinated or otherwise treated hot tub water is regularly in contact with these areas – even the top edge of the spa that is in contact with the cover. Use a mild chlorine solution as mentioned above.
  4. Refill the spa to just above the jets.
  5. Shock with four times the normal dose of SpaGuard® Chlorinating Concentrate.
  6. Turn on the jets and circulate for 2 – 3 hours. The bacterial growth usually builds up in the lines, so it is necessary to flush them thoroughly.
  7. Just before draining the spa again, add a plumbing line cleaner such Spa System Flush or Swirl Away to help break up any build up of bio-film in the lines (this is a good maintenance step to take any time that a spa is drained and refilled)
  8. Refill with fresh water.
  9. Chemically clean (use a cleaner such as SpaGuard® Filter Cleaner®) and / or replace the filter. Chemically cleaning the filter helps to remove accumulated greases, oils, dead skin, etc.
  10. Rebalance spa and shock. Chlorine level: 1.0 – 3.0 ppm, Bromine: 2.5 – 5.0 ppm; pH 7.4 – 7.6, Total Alkalinity 100 – 140 ppm, Calcium Hardness 200 – 250 ppm. (if using other types of sanitizers, be sure to follow all manufacturers' label instructions). Do not enter spa until until sanitizer (chlorine) level drops below 4.0 ppm.
  11. As an additional precaution, we STRONGLY RECOMMEND cleaning the underside of the spa or hot tub insulating cover with a product such as BioGuard® Stow Away® (contains quarterly ammonium compounds, which when used properly controls mildew). Clean your cover with Stow Away® whenever you drain, clean & refill your spa or hot tub. You may further want to use a product such as Pristine Mist which helps control odors and discoloration on the inside spa cover insulating foam.
  12. Not cleaning the cover could have re-contaminated the spa or hot tub surface with the PA bacteria.

Please be sure to contact your physician if a skin rash occurs. DO NOT SELF DIAGNOSE any physical conditions. This article is for information purposes only.