I sent my internist an email, asking his opinion of the thought that this might be a "Herx" (don't know whether I should be using that word as a noun, a verb, or an adjective!) and his response was very disappointing. To paraphrase, he said that a Herx reaction is something suffered by patients after a bout of sepsis. He went on to say, in a very smart-@ss way if you ask me, "and, as far as I know, you've not recently HAD Sepsis, so I doubt this could be a Herx reaction."
Alrighty then....
Everything I've read today seems to indicate certain conditions that are associated, especially Lyme. I tested positive for Lyme several years ago, but was told that the level was "too low to cause any problems".
So, I don't know why I'm hurting, but I'd be very happy to go back to my pre-Levaquin level of discomfort!