Published On: May 30th, 2025

One of the biggest obstacles to kids getting appropriately diagnosed with PANS/PANDAS is the suddenness of behavior changes. This is especially true when working with someone who doesn’t specialize in PANS/PANDAS because the available diagnostic criteria require that there be an abrupt onset of behavior change.

The published criteria for a PANDAS diagnosis requires that there be an abrupt onset of OCD and/or tics, and for PANS it requires an abrupt onset of OCD or ARFID (avoidant restrictive food intake disorder). And yet, there was a study that was published by the team at the Stanford PANS Clinic that found that only 40% of the patients reviewed that met the symptom criteria for PANS/PANDAS had sudden onset.

So, what could be contributing to the disconnect?

These are just my thoughts from a decade of working with PANS/PANDAS and what our team at Resilience Naturopathic has seen with the thousands of kids we have worked with. We haven’t done any official research or analysis, so you won’t find this in a published journal. Nevertheless, I think there are a few main things that happen.

First, I think that many people see signs early on that they are told are normal or transient for young kids. The challenge is that this is legitimately true for many kids. Things like tics, stammering, repetitive behaviors, need for things to be a certain way, and mood and impulse control issues, are all normal things for young children to experience. Many parents won’t even seek help for these things because information about developmental leaps are readily available online. Others do seek help and are reassured by their pediatrician that this will pass, and they just need to wait.

For most people, it does pass. For those with PANS/PANDAS, they too often pass, but then come back. They might pass yet again, only to come back, often worse each time. It is only after the pattern of these symptoms relapsing and remitting with increasing severity each relapse, that they start to seek more intensive levels of help. At this point when asked if it came on suddenly, many will say no, because they have seen this pattern before. Once it becomes clear that they are dealing with PANS/PANDAS they are then able to look back and see the beginning of the pattern when they likely had a sudden onset.

Second, some kids are born into immune or neurological challenged states, whether from an infection they got from their mother in utero, at birth, or some other immune activation or toxic exposure that their mother dealt with while pregnant, even if it isn’t transmitted to the baby. When you are born with challenges, you can still get PANS/PANDAS, but it can be really hard to pin down the exact onset when you have many things you are already dealing with.

Third, you could be living in constant environmental exposures. The most common culprit is mold, but chemicals could also be a factor. Most people aren’t going to get immediately sick from their first exposure to something toxic, even if they have a higher susceptibility to it. It typically builds over time. With the initial exposure, your body is likely able to do enough detoxification that you barely see any symptoms. But with each repeated exposure, you are increasing the demand on your body, which can weaken the immune system and detox pathways. As these systems are weakened, you will see more buildup of whatever it is you are trying to clear, and symptoms will start to appear. They can come on gradually like little alarm bells to tell you something is wrong. As the buildup continues along with the exposure, more alarm bells are needed. In these cases you will often see an insidious build-up, and possibly multiple diagnoses piling on top of each other. It often becomes more clear when you start looking for something that can tie all of the symptoms and diagnoses together. When people realize that the immune system is the connecting factor, it becomes more clear that is PANS, even when there isn’t a clear sudden onset they can identify in retrospect.

Fourth, is a combination of the insidious nature of constant exposure plus an added infection that leads to a sudden and significant worsening. This might be the toughest one for people, because they have a clear worsening, but because of the previous history, it isn’t technically within the criteria for the diagnosis. Some non-PANS/PANDAS specialist providers will search for other explanations for why the existing symptoms suddenly got worse.

This fourth factor is made significantly more challenging by the fact that many kids don’t have typical signs of illness – they only have neuropsychiatric symptoms. So parents might not even know to look for illness and instead are looking at behavioral interventions, problems at school, etc. It is only when looking for evidence in blood work that the infection becomes clear. And even this isn’t guaranteed to be an effective way to evaluate. Some children with PANS/PANDAS have broader immune dysfunction and are unable to appropriately produce the antibodies that we look for as evidence of infections or exposures.

So, if you are seeing symptoms that are in alignment with PANS/PANDAS (check our page on all the symptoms with some useful descriptors of what this actually looks like in real life here), this could be what you are dealing with even without the sudden onset. Knowing that a misdirected immune response is at the core of the mental and behavioral health symptoms is vital for effective treatment, especially if you are using conventional or functional medicine. It even matters in homeopathy, not to the point that it will direct which homeopathic remedy is recommended, but it will inform how to effectively manage the case to resolution. Regardless of the approach to healing you opt for, working with a PANS/PANDAS expert will get you the best results.

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