• A sudden, dramatic onset of severe anxiety, obsessive-compulsive symptoms, tics, or other behavioral changes in children.
  • Triggered by various infections (like Lyme, mycoplasma, strep, viruses), immune issues, or even environmental triggers.
  • It’s not tied to just one specific infection.



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  • A type of PANS, but specifically linked to strep infections.
  • The body’s immune system reacts to strep bacteria, but mistakenly attacks parts of the brain (especially the basal ganglia), leading to sudden psychiatric and neurological symptoms.


  • Both involve a sudden, extreme change in mood, behavior, or movement in children.
  • Both are thought to be caused by an abnormal immune response that ends up targeting the brain.
  • Both can lead to OCD, tics, severe anxiety, eating restriction, sensory sensitivities, regression, or rage episodes.


  • PANS = broad term, many possible triggers (bacterial, viral, environmental, immune).
  • PANDAS = specific to strep infection as the trigger.
  • You can think of PANDAS as one “branch” under the larger “tree” of PANS.

 When we talk about PANS, PANDAS, and CIRS, we’re really talking about a trigger that leads to the same destination: brain inflammation and immune system confusion.

In CIRS (Chronic Inflammatory Response Syndrome), we need a perfect storm of events. 
  • Genetics (not always)
  • Exposure to biotoxins 
  • A priming event 

The exposure is often a biotoxin from mold, water-damaged buildings, Lyme disease, or other sources, but we need a priming event like a viral illness, trauma, or inection. In PANS/PANDAS, the trigger is often an infection—like strep, mycoplasma, or a virus. But in all three, the problem is not just the trigger itself—it’s how the immune system overreacts and begins to attack the body, including the brain.

The result? 
  • Inflammation in the central nervous system
  • Sudden mood changes, OCD-like behaviors, anxiety, brain fog, or regression
  • Physical symptoms like fatigue, headaches, sleep disruption, or tics

This is why CIRS can sometimes be mistaken for, or even overlap with, PANS/PANDAS—especially in children. A child living in a water-damaged home could be diagnosed with PANS/PANDAS if their symptoms flare after an infection, but the underlying immune dysregulation might actually be fueled by biotoxin exposure and the upregulation of gene expression (HLA-DR).
Bottom line:
 Whether it’s strep, Lyme, mold, or another trigger, the immune system’s misfire on the brain can look and feel very similar. Identifying the root cause is key so treatment can calm the immune system and allow the brain to heal.
In this study Dr. Scott McMahon reported that out of 33 children clinically diagnosed with PANS or PANDAS, all 33 showed biomarkers consistent with CIRS; after treating for CIRS, 94% improved CIRS symptoms, and over 80% had reduction in neuropsychiatric symptoms and medications.

Link: Discovering a cure for PANS (Pediatric Acute-Onset Neuropsychiatric Syndrome

  • McMahon, S. W. & Dorninger, E. (2025). Discovering a cure for PANS (Pediatric Acute‑onset Neuropsychiatric Syndrome). Vitality Hour [Audio podcast]. YouTube.
  • Dr. Sandeep + Dr. McMahon