Mold and PANS

Mold is the Boogie-Man of PANS

Mold is everywhere, and it is invisible. Families of children with PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) are searching for answers. Often a clear trigger like strep or another infection isn’t identified, so it is natural to ask:

Could mold be the cause?

This question comes up frequently — and understandably. But while mold exposure is common and testing often shows “positive” results, the scientific link between mold and PANS remains weak and unproven. This post explains why.

What we know about PANS

PANS is defined by:

• Sudden, dramatic onset of symptoms (often overnight)

• OCD, restrictive eating, tics, anxiety, emotional lability, or regression

• An episodic course, with flares and remissions

• Strong evidence of immune-mediated brain inflammation

In many cases, PANS follows an infection. In others, the trigger is not clearly identified — but the immune pattern of the illness is still recognizable.

Why mold often enters the conversation

When no infection is found, families and clinicians naturally look for something that could explain what’s happening. Mold becomes a common focus because:

• Mold is everywhere

• There are many available tests

• Symptoms attributed to mold (fatigue, brain fog, irritability) overlap with PANS symptoms

However, overlap and availability do not equal causation.

Everyone has mold exposure — and that matters

This is a crucial point:

100% of people are exposed to mold.

Mold spores are present in:

• Indoor and outdoor air

• Food

• Dust

• Buildings, even well-maintained ones

Because exposure is universal, most people will show detectable markers of mold or mycotoxins if tested — whether they are sick or completely healthy.

A test that is “positive” in nearly everyone cannot tell us who is ill because of it.

Why mold tests are so often “positive”

Many mold and mycotoxin tests are:

• Very sensitive

• Poorly specific

• Lacking clear thresholds for disease

In most cases, these tests reflect:

• Normal environmental exposure

• Normal detoxification and excretion

• Background immune activity

Importantly, mold test results:

• Do not predict PANS onset

• Do not correlate with symptom severity

• Do not predict who will respond to immune treatment

A positive test does not mean mold is the cause of PANS.

Correlation is not causation

PANS symptoms fluctuate. Testing is often done during flares, when families are understandably searching for answers. When a lab result comes back abnormal, it’s easy to assume:

“We found mold — therefore mold caused this.”

But this leap is not supported by evidence.

There is:

• No clear timeline linking mold exposure to sudden symptom onset

• No proven mechanism connecting mold to the specific immune process seen in PANS

• No consistent clinical response that confirms causation

  
  

Why mold does not match PANS biology

PANS is characterized by:

• Abrupt onset

• Immune dysregulation

• Brain inflammation

• Often dramatic improvement with immune-modulating treatments

  
  

Mold exposure, by contrast:

• Is chronic and ongoing

• Does not cause sudden overnight changes

• Has not been shown to trigger the specific immune patterns seen in PANS

• Does not target the brain in a PANS-specific way

The biology and timeline simply do not align.

Does treating mold help PANS?

This is one of the most important questions.

Families are often advised to pursue:

• “Detox” protocols

• Binders

• Antifungals

• Saunas

• Extensive home remediation

  
  

In clinical practice, however:

• Core PANS symptoms (OCD, tics, emotional dysregulation) usually do not improve

• Any improvement is often mild, temporary, or non-specific

• Children who respond strongly to immune treatments often show no meaningful response to mold-directed therapies

In short: Treating mold rarely treats PANS.

Why the mold narrative is so appealing

The mold explanation persists because it:

• Offers a concrete target

• Feels actionable

• Reduces uncertainty

• Provides a sense of control

But a comforting explanation is not always a correct one.

A balanced, honest perspective

A more accurate way to think about mold is this:

• Mold is not a proven cause of PANS

• Mold exposure is common and usually non-specific

• In some individuals, it may contribute to general inflammation or discomfort

• Treating mold does not replace treating immune-mediated brain inflammation

Addressing overall health matters — but it should not distract from the core nature of the illness.

The bottom line

• Positive mold tests are common and expected

• There is no evidence that mold causes PANS

• Treating mold rarely improves core PANS symptoms

• PANS remains best understood as an immune-mediated neuroinflammatory condition, even when the trigger is unknown

• I am open to new evidence and to patients' lived experiences, there is always more to learn, I am happy to engage in a conversation with any patient to whom this is an important part of their worry or experience.