"Are there any hypo-allergenic spa chemicals available on the market?"

nope

"Can I use chlorine in a stand-alone spa"

absolutly!

"would switching to chlorine help?"

maybe yes, maybe no.... only way to find out is to try it.

"Any thoughts?"

YES!!!! PLEASE consult with a qualified doctor that's willing to take the time and effort to properly diagnos what's causing your problem. It could be the chemicals, or 100 other things. You may find a solution through trial and error, however you could also make thing worse. There are MANY MANY different things that could cause this condition, and chemicals are only one possibility.

I have the same problem myself. We use Baquaspa, and after using the tub for about a year, I have started getting what looks like little white pimples a few days after I use the tub. Funny thing is I only get these on my legs and nowhere else (yet) They are fairly sensitive to pressure, and the first couple of times I got them, I tried to pop them like a pimple, and they got REALLY infected. Now I just leave them alone and they go away in a few days.

My wife uses the tub just as frequently and she doesn't have any problems.

try nature 2 or spa frog - works well with chlorine - totally incompatible with baquaspa

spec

If you change from one chemical to another, BE ABSOLUTELY SURE you have flushed the spa at least 2 times with clear water before introducing a new chemical. Get new chemical feeders, measuring spoons, etc. For instance, bromine and chlorine mixed can become explosive!

Others are correct, in that it may or may not be the chemical. It could be a chemical imbalance in the water. Have you tried a 7 way test kit to ensure all the portions of the water are in check? Also, does this condition occur immediately after a complete drain down and fill of the spa (including chemicals)? Have you switched soaps, deodorants, laundry detergents, etc, about the time this started? Chemicals react differently with different chemicals. Could be chemical brand even.

I had the same problem occur after years of using bromine/chlorine. I ended up becoming sensitive to the chemicals and switched to Baqua Spa products. I no longer have any skin problems. I have talked to a few people that experienced the rash with bromine/chlorine and also swtiched to Baqua Spa and no longer experienced the skin problem. If you do not have anyone near you that sells the product, you can go online and there are several companies/stores that ship. Hope this helps.

we're not really sure if the chemicals in your tub have cause your allergies, so it may or may not the chemicals are causing your problems. Try consulting your MDs to check and rule out possibilities of whats causing your allergies.

If such product doesn't give you the benefits, why would you stick to it? Think of the benefits that you would garner before you put yourself into it. There are lots of spa products out in the market. Try to use the one that you really sure of and the one that you rely using. The one that wouldn't result to any skin allergy. There are products that are made of strong chemical reactions but there are too that are quite of little. Choose products that are made of little chemical aspects. Also, have a skin allergy kits with you. You can avail of it any medical store. But be sure to choose the right allergy kits to treat your skin allergy.