I got hives in week 3. Started out as a few spots that looked like bug bites and got worse throughout the day. I didn't realize they were hives as never had them before. My left ankle and foot also swelled up to point I couldn't wear my shoe. It was now 10pm, Urgent Care was closed so I ended up at ER - probably the most expensive benadryl I've ever had
It happened again a few days later. I narrowed it down to either extra supplement my Chiropractor gave me that has Alpha-Lipoic Acid or to an artificial sweetener in some of the products, acesulfame potassium. I've never been allergic to anything. I stopped taking the supplement and any products with that sweetener and I've been fine.
My Dr. has had patients allergic to Alpha-Lipoic Acid before and turns out it messes with thyroid medication, which I am on. So a real no-no for me to take.
I'm going to try one of the products with the acesulfame potassium again in next week or so and see if it comes back.
My Dr. said you can build up a reaction over time to something, so that may be way it took a couple of weeks for something to happen. Or, it may have been some completely unrelated to the IP diet.
ETA. My DH didn't have any reaction to the diet when he was on it.