Every day at work I drink tea in the morning with Splenda, and everyday my hands swell to the point that I cant remove my rings.  Ive tried different combinations of caffeinated and non-caffeinated teas, and different or no sweetners to try to figure out what can be causing the swelling and nothing has helped.  My only other thought is that it could be the filter in the line leading up to the pot.  The filter is an Everpure IN-10, and when I look at the spec I notice that Hexametaphosphate crystals are used in this filter.  Could this be causing the problem.  By the way, I do have high bloodpressure and take a medication which contains 12.5mg of HCTZ and an additional 25mg of HCTZ each day.
HI, thanks for using Chat Doctor It can be difficult to determine the source of an allergy. IF you are not able to determine the cause by elimination it is sometimes the best option to have allergy testing done. This can be done by blood tests or skin prick testing. Allergy testing can be done against a range of agents and would be able to pick up what is causing your symptoms. I hope this helps