Report Leaving On a Jet Plane....(With a Raging Child) in PANS / PANDAS (Lyme included) Posted April 11, 2013 tu4 -- what is she taking now? i went to the TACA meeting this weekend where 2 of the docs said that if you give a med and see a worsening and then give charcoal and get improvement, it's likely a herx. did you recently start her on something new to have the charcoal produce that? Yes, that is my thinking, too. We have seen this happen when we started cefdinir. However, she was off of all meds....makes me think that there is something like yeast constantly producing toxins that the charcoal can mop up . And yeast has always been an issue for her.