12/11/2025
PANS: When immune and metabolic dysregulation look like bad behaviour
When a child’s mental health symptoms appear almost instantly, within 24 to 48 hours, it’s importanr to take a holistic view of their behaviour.
Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) occurs when infection, immune dysfunction, or metabolic disruption triggers abrupt changes in mood, behaviour, or cognition.
A child who was previously thriving may develop, within days:
Obsessive thoughts or compulsive behaviours
Regression in handwriting or an unexplained onset of inability to do their school work
Intense anxiety, depression, panic, tics or rage-like outbursts
New eating habits, particularly food restriction
New sensory sensitivities
These symptoms are not purely psychological; they reflect neuroinflammation, immune activation, and specific metabolic pathway changes caused by inflammation, blood-brain barrier disruption, and energy metabolism dysregulation within the brain.
Recent metabolomic research has shown that children with PANS exhibit distinct biochemical profiles compared with healthy peers including altered levels of neurotransmitter-related metabolites (tryptophan, glycine, histamine/histidine) and markers of oxidative stress, glutamine imbalance, and mitochondrial energy deficiency. These findings point toward disruption of the tryptophan–kynurenine pathway, linking immune activation and neuroinflammation with psychiatric symptoms.
Behavioural support for children, particularly from the age of 3 to puberty, we need to look at the whole picture and recognise when the immune and metabolic systems are driving changes in the brain to create this PANS behaviour
DOI:10.3389/fnins.2021.645267