Having seen your update I would not wait, but rather go ahead and resume treatment. for the anxiety.
This happened in October for the first time. I immediately took her to a child behavioral therapist who did cognitive treatment for anxiety. I didn't feel in my gut that was it, so I continued researching on my own. I stumbled upon articles about PANDAS and immediately saw exact comparisons to mild cases of that. Desperate, I showed the parallels to our pediatrician, and my daughter was tested for strep. Her test came back positive and we started a z-pak. After two days of antibiotics she was back to norm and the nightmare appeared to be over. Two weeks ago, out of the blue, she said it was happening again. Immediately we started another round of antibiotics, but it did not help this time. Over the last 2 1/2 weeks, she has said her brain has done this on 3 different occasions. I talk to her and let her know it will be okay and I will be there with her each step of the way, but of course I'm worried and terrified at what the culprit is. Do I try to wait it out a little longer?
Based solely on a single type of behavior, cautuon must be exercised in suggesting what might be occurring. Having said that, one possibility is the emergence of an obsessive-type Obsessive-Compulsive Disorder. For now this does not invite any immediate concern. If it persists over the next couple of months I would arrange an evaluation with a pediatric mental health professional.