Mysterious Rash - In deep trouble with wife.

[sbt99]

It's the wife who has the rash, not me

Background:
- 1250 gallon in-ground spa
- Previously chlorine, serviced by spa-guy.
- Converted to bromine, serviced by idiot-husband (me). Established sodium bromide level, shocking with Leisure Time Renew (MPS). Using test trips while I wait for my test kit to come in - levels are fine according to strips (inaccurate, I know).
- Spa is not kept heated. Heated only for occasional (once every few weeks or months) use.
- Spa is irregularly shaped/located, so I've only recently put on a bubble-wrap like cover to reduce evaporation and debris.

A few weeks ago, the wife dangled her legs in the spa, while using her hands/arms to pick up some leaves that had fallen in. Not long after that, she developed a rash (follicullitis, probably) that was terribly itchy, many tiny red spots.

Her dermatologist prescribed antibiotics and said it was probably pseudomonas from the spa (seems to jive with the only areas exposed to the spa recently, arms and legs.

While I'm not discounting that possibility, as the bacteria may have established itself while I was transitioning to bromine, I wonder if another possibility is a sensitivity to the MPS-based shock that I'm using? Perhaps I should switch to another oxidizer (dichlor?)...

I should point out that I've been fine.

I'm going to order some bacteria test strips to make sure, but has anyone else seen anything like this? I'd hate to have to drain/sanitize the spa without figuring out exactly what the issue was.

 

[chem geek]

See this link that has some info to help distinguish between a chemical reaction vs. a bacterial infection. Since this came on in < 24 hours and was terribly itchy, this sounds more like a chemical reaction, but the doctor (dermatologist?) should have been able to figure that out if thy did a skin test. I'm not a doctor so am not giving advice here -- I'm just making a comment/observation.

Have you used bromine tabs? The DMH in tabs can be irritating. MPS can also be irritating [EDIT] (technically it's the minor component of potassium persulfate that is irritating -- see James' post below). [END-EDIT] Why did you switch from using chlorine to using bromine? How did the service guy maintain chlorine in the spa since you usually have to add chlorine every day or two (he wasn't using Trichlor pucks, was he)?

 

[JamesW]

Renew contains some potassium persulfate (potassium peroxydisulfate K₂(S₂O₈)). Persons allergic to persulfate can develop itching and rashes with fairly low exposure.

http://www.poolwater.com/msds/all/Leisu ... 0Renew.pdf

The Hidden Hot Tub Allergen
“The patient did not react to the chlorine or bromide, which the typical patient would. However, he did react to the sodium metabisulfite and ammonium persulfate. Ammonium persulfate was used to screen for contact allergy to the potassium persulfate used as shock treatment in the patient’s spa (and it’s also used in many bromine-based pool and spa chemical systems).”

The patient switched to a chlorine-based sanitizer and shock treatment and began to use other chemicals to adjust the pH levels in his spa. Soon after, his condition cleared.
http://www.the-dermatologist.com/article/3002

Persulfate can also be found in a few personal care products, such as some hair bleach and denture cleaner.