saidie10

Yes, we had severe OCD, then a couple of years of normalcy, and then an awful flare after some sickness.

My son has been on Zithromax for over a year (500mg 3x a week) and his Dr. wants him to be on it until he has and adult immune system. We have discovered that when he goes off the antibiotics, he starts to relapse.

There are a few possibilities and others have mentioned some of them. Has he had a vaccine in the last few weeks or months? That triggers new or returning symptoms in some. Have you moved or changed schools? That could indicate something in the new environment, such as mold. Any recent dental work? That can be a trigger for some. I agree with HopeinHIM - if he hasn't been evaluated by an LLMD for Lyme, Bart, etc, this would be a good time. These infections deplete the immune system and can cause allergies, immune deficiency and autoimmunity.

Clearly, you'd want to look for infections.  I'd set up an appt with your pandas doc (or whoever; really, any doc who will do it) to run some bloodwork ASAP, both for infections and immune system stuff, IgG levels and so forth.
In the meantime, I'd haul the kid off to the nearest urgent care for a swab and throat culture today.

It seems to me that this sort of situation is to be expected with PANS/PANDAS.

Perhaps he has a new infection.

Check for bartonella!  Lymes co-infection.   Our son raged and OCD out of no where.   If he is young it could be he is entering puberty and that can rock their world as well. For us it was three long years and the fear is always there. We cleaned up his diet and gave supplements based on organic urine test and 23 n me test. Best thing I ever did!!
His ups and downs now are mild compared to before (no soy, dairy or gluten)  He tells us his brain is calm now.  We found that he was depleted of B1 and B2 as well by the test results. I thought big deal when I heard that but big change once we started to supplement.  
Our immunologist claims that these children have innate immune response to various triggers depending n their genetic predisposition. This causes inflammation and the mental symptoms are a response to that inflammation.

Our DD had all the clinical symptoms of pandas/pans. Evey doctor she has seen concluded that her symptoms were pathological and not behavioural. She was diagnosed in her 4th month by her PCP as having an unknown autoimmune illness. We didn't care what the doctors called her illness as long as that could treat it/manage it. Along with the diagnosis comes insurance and/or social services funds. We moved from southern California to Washington state in 2013 almost 2 years after the onset with no pandas diagnosis. Dd's diagnosis of pandas came from her physiatrist at Seattle childrens he ordered the Cunningham panel as a confirmation of the diagnosis so he could refer us to a pandas specialist. The Cunningham panel to diagnose pandas/pans provides evidence for the more expensive ivig and plasmapheresis treatments which can be used in part to get insurance to pay the bill. The majority of the plethora of blood tests ordered by various doctors to find the causes of dd's symptoms, be it positive and negative got us nowhere toward being able to manage dd's symptoms. The history of tests does help rule out many co-ailments. A second panel would not do us much good, unless DD's symptoms changed. We know that dd needs mitochondrial support and her neurologist is ordering a mitochondrial panel so that we can adjust the supplements according. Without the Cunningham panel, we wouldn't be where we are today in managing and treating dd's symptoms. Her pandas specialist has helped us tremendously reducing the intensity of DD's symptoms.

We have seen Dr Rao since our onset back in late 2013. He is very knowledgeable on PANS/PANDAS and spends a great deal of time with patients. This being said, you often have to wait a long time to be seen in the patient room. However, as long as he is spending time with us and being thorough (which he does), I dont' have an issue. Just be prepared to wait or plan to get an early appt in the morning. The staff is helpful, especially Lori, and we have been pleased so far.

I absolutely KNOW that my pandas 12dd has very dilated pupils during anxiety or OCD. Without a doubt. I think it is a very common phenomenon with any type of anxiety.