Were you able to figure out what caused the reaction?

No! I'd eaten dinner hours ago (and I've never had any food allergies beyond the migraine trigger in caffeine), the last thing I'd taken by mouth was my customary night meds, I hadn't changed my brand of toothpaste or soap or shampoo . . . It doesn't seem to be recurring tonight, so I am guessing it was some kind of immune system freakout, but it had better not come back.