Understanding PANS and PANDAS: A Look at Neuropsychiatric Disorders

Pediatric Acute-onset Neuropsychiatric Syndromes (PANS) and is a condition of immune-mediated neuroinflammation that primarily affects children. It is characterized by a sudden and dramatic onset of neuropsychiatric symptoms, following an infection, virus or environmental trigger exposure.

Potential symptoms can include:  

• Obsessive-Compulsive Disorder (OCD) – like behaviours: This is a common feature, with children experiencing intrusive thoughts and repetitive behaviours.

• Restrictive Eating: A sudden onset of severe fussy eating is characteristic of PANS and one of the key diagnostic criteria.

• Tics: These are sudden, repetitive movements or sounds that children cannot control.

• Anxiety: Children may experience severe anxiety, including separation anxiety and panic attacks.

• Mood Swings: Rapid and intense shifts in mood, from irritability and aggression to sadness and depression.

• Behavioural Regression: Children may exhibit behaviours that are typical of younger children, such as bedwetting or tantrums, or even forgetting skills such as writing their name or using cutlery.

• Motor and Sensory Abnormalities: Difficulties with coordination, handwriting, and sensitivity to light, sound, or touch.

PANS Triggers

PANS is caused by a virus or pathogen. The illness does not have to be severe; there are even cases of mild colds triggering PANS episodes. Symptoms can begin within a couple of weeks of an illness so it can be difficult to identify the cause. PANS can be episodic, and symptoms can resolve and then recur with subsequent exposure to triggers for some children. For other, symptoms can become chronic and a long-term concern.

The most commonly reported PANS triggers are:

• Streptococcus Group A (This is recognised as a subtype of PANS, called PANDAS.)

• Epstein Barr virus

• Herpes simplex

• Coxsackie virus (Hand, Foot & Mouth)

• Influenza

• Varicella (Chicken Pox)

• Impetigo (school sores)

• Pneumonia

• Mould (This is often a slower onset and can be misdiagnosed)

• Candida overgrowth

For many children, PANS is not caused by a single trigger but by a cumulative load. A child may have underlying mould exposure and then experience an acute onset when they contract a common cold or a flu.

Diagnostic Criteria

The current accepted diagnostic criterion for PANS is:

Abrupt, dramatic onset of OCD or severely restricted food intake Additional neuropsychiatric symptoms, plus at least two of the following symptoms:

• Anxiety

• Emotional lability and/or depression

• Irritability, aggression, and/or severely oppositional behaviour

• Behavioural regression

• Deterioration in school performance

• Sensory or motor abnormalities

• Somatic symptoms, including sleep disturbances, enuresis, or urinary frequency

And that these symptoms not better explained by another neurological or medical condition.

What is PANDAS?

PANDAS is a specific type of PANS. It occurs when these neuropsychiatric symptoms are triggered by a streptococcal infection, such as strep throat. Streptococcal infections can become antibiotic resistant, and the bacteria can form biofilms in the body, a protective barrier that can be even more resistant to antibiotic treatment or antimicrobial herbs. There are treatments that can help to break down these biofilms to allow for more effective treatment and recovery.

What is the underlying cause of PANS and PANDAS?

The exact cause of PANS and PANDAS is not fully understood but current research suggests they result from an abnormal immune response - often triggered by infection (such as group A streptococcus in PANDAS) - that leads to inflammation or autoimmune attack on brain regions involved in behaviour and movement, with genetic vulnerability, other infections, environmental factors and immune-regulatory differences all likely contributing to why some children are affected while others are not.

Autoimmune Response

Previous theories suggested that PANS occurs when the body's immune system mistakenly attacks certain areas of the brain, particularly those involved in movement, behavior, and emotions. This misdirected immune response can cause inflammation and disruption of brain function. This has since been disproven, and there is no evidence that PANS is an autoimmune process.

Innate vs. Adaptive Immunity

Current research into the underlying causes of PANS has shifted toward a multiple system hypothesis. It suggests that PANS is not caused by a single factor, but rather a convergence of genetic susceptibility, immune priming, and environmental triggers that lead to autoimmune encephalitis (inflammation of the brain).

 PANS is characterized by a perfect storm of immune dysfunction where the innate and adaptive systems create a self-perpetuating cycle of neuroinflammation.

• Innate Immunity: This is the body's first line of defense, providing a rapid but non-specific response to infections.

• Adaptive Immunity: This is a more specific and long-lasting response, involving the production of antibodies that target specific invaders.

The innate immune system’s role in PANS is characterized by the chronic activation the brain’s immune cells, the microglia. These cells enter a hyper-inflammatory state of neuroinflammation. The innate immune system gets stuck in a loop of pro-inflammatory cytokines which disrupt essential dopamine signalling. These inflammatory signals compromise the integrity of the blood-brain barrier, allowing systemic inflammation to perpetuate neurological distress.

The over-expression of inflammatory cells and proteins as part of the immune response results in the innate immune system has developing a form of biological memory. This causes the system to become hypersensitive, leading to excessive inflammatory responses even when faced with minor, non-specific environmental triggers. Because the immune system remains in this heightened state of readiness, neuropsychiatric symptoms can continue or flare up easily. This creates a lasting cycle of neuroinflammation that often persists long after the original infection has cleared.

The Blood-Brain Barrier (BBB) Link

Immune cells activated by infections in the gut or nasal cavity produce inflammatory markers which physically degrades the tight junctions of the blood-brain barrier. This breach creates a "leaky brain" environment, allowing circulating inflammatory cells to cross into the central nervous system and bind to neuronal targets, such as Dopamine receptors, directly causing the sudden onset of neuropsychiatric symptoms.

The Microbiome Link in PANS

There is a rapidly growing body of evidence linking gut microbiome dysfunction (dysbiosis) to the severity and onset of PANS. The gut is now considered a primary site for the immune priming that leads to neuroinflammation.

Studies comparing the microbiomes of PANS children to healthy controls have found a distinct signature:

• Low Diversity: PANS children often have significantly lower microbial diversity, particularly in beneficial Short-Chain Fatty Acid (SCFA) producing bacteria. One key SCFA is butyrate, is known to cross the BBB and calm microglial activation. This results in less anti-inflammatory protection for the brain,

• High Pathobionts: There is often an overrepresentation of pro-inflammatory microbial species such as Bacteroides and Prevotella, which can drive the production inflammatory cytokines that weaken the blood-brain barrier.

·         Intestinal Permeability: The "Leaky Gut, Leaky Brain" connection is a major focus of current PANS research as elevated markers of intestinal permeability are frequently found in PANS patients. When the gut lining is compromised, bacterial components Lipopolysaccharides leak into the bloodstream, causing systemic inflammation that keeps the microglia in the brain in an activated state.

• Altered Neurotransmitter Metabolism: The gut produces most of our brain’s chemical messengers. Instead of producing Serotonin, the body may shift toward the Kynurenine pathway, which produces neurotoxic metabolites that exacerbate anxiety and tics.

Key Differences Between PANS and PANDAS:

PANDAS (Paediatric Acute-Onset Neuropsychiatric Disorders Associated with Streptococcal infections) is a subtype of PANS specifically linked to streptococcal infections, while PANS can be triggered by various infections. Previous research on PANS has focused solely on PANDAS has having a single infection trigger allowed researchers to study the immune response with more clarity, facilitating the development of diagnostic tools and treatments. Much of this research can be applied to PANS, as the umbrella diagnosis.

Testing for PANS

PANS is a clinical diagnosis, which means that there is no one biomarker or definitive test that can confirm a PANS diagnosis. There are some antibodies and inflammation markers that can occur with PANS, but they are not present in all occurrences. A detailed medical history and clinical assessment can help to determine if PANS is the most likely diagnosis.

Naturopathic Treatment for PANS

Erin Dalton, Naturopath

Naturopathic management of PANS focuses on shifting the body from a state of chronic immune defence to one of resolution by addressing the underlying drivers of neuroinflammation. Utilising targeted herbal medicines and nutrients to modulate the innate immune system, practitioners can reduce the production of pro-inflammatory cytokines and calm the microglia. Concurrently, a foundational focus on microbiome restoration—addressing intestinal permeability and promoting beneficial keystone species—helps close the leaky gut that often fuels the leaky brain. This systemic approach works to repair the blood-brain barrier and stabilise immune signalling, effectively lowering the child’s hypersensitivity to environmental triggers. By resolving these physiological imbalances rather than just suppressing symptoms, naturopathic treatment aims to break the cycle of neuroinflammation and provide a roadmap for long-term clinical resilience.

If you suspect your child’s recent behavioural change may be a result of PANS then book a time for a Free Discovery Call to discuss treatment options.

Disclaimer:

The information provided in this article is for your personal or other non-commercial, educational purposes. It should not be considered as medical or professional advice. We recommend you consult with a GP or other healthcare professional before taking or omitting to take any action based on this article. While the author uses best endeavours to provide accurate and true content, the author makes no guarantees or promises and assumes no liability regarding the accuracy, reliability or completeness of the information presented. The information, opinions, and recommendations presented in this article are for general information only and any reliance on the information provided in this article is done at your own risk.

Any third-party materials or content of any third-party site referenced in this blog/article/handout do not necessarily reflect the author’s opinion, standards or policies and the author does not assume any liability for them whatsoever.