Eating disorder or infection? PANS, PANDAS and other rare conditions

What's the link between PANS / PANDAS / infection and an eating disorder?

It's possible — but rare — that some eating disorders that co-occur with extra-bizarre symptoms are the result of brain infection. If so, medication may be needed in addition to the usual eating disorder treatment.


  • This page is only relevant to you if your child’s eating disorder is accompanied by unusually bizarre symptoms.
  • How bizarre? I describe some of the more bizarre symptoms of a standard eating disorder, so you can compare.
  • If you think your child’s symptoms might match those of an infection in the brain, then consult your clinicians as some medical treatment may be indicated.

Caution: be careful with Dr Google

  • These brain infection conditions — PANS, PANDAS, BGE — are thought to be rare. The field is quite new, some find it controversial.
  • On this page I compile what may be a mixture of science, clinical observation and … opinion. I don’t have the expertise to judge the validity of any of this. And by the time you read this, things may have moved on.
  • So please consult your clinicians, not Dr Google, and not me!
PANS PANDAS Inflammatory brain disease
Caution: we don't yet have a huge amount of clarity on these brain conditions

Is your child’s eating disorder extra-bizarre?

An eating disorder brings weird behaviours and beliefs. Malnourishment alters brain functioning. This is all ‘normal’.

But if your child’s eating disorder is accompanied by extra-bizarre symptoms, the cause might be inflammatory brain disease, and there are medical treatments to pursue.

If your son or daughter has anorexia nervosa, atypical anorexia nervosa, or ARFID, combined with obsessive-compulsive disorder (OCD), and various motor, neurological and psychiatric symptoms, then present the clinicians with all the signs you observe, because they may consider inflammatory brain disease.

All the more so if some of this happened suddenly and dramatically.

Does this disease change the treatment?

I am flagging up the rare possibility of inflammatory brain disease because in addition to all the normal work required to treat an eating disorder, there may be treatments for the brain inflammation component: antibiotics, non-steroidal anti-inflammatory drugs, steroids, and so on.

steroids, NSAID, antibiotics - eating disorders

This is not INSTEAD OF refeeding

It’s vital that you understand this: it’s most likely you will also need to continue the normal eating-disorder treatment. And if you haven’t begun standard treatment, do so now without any delay.

Do not let anything here distract you from the main work of helping your child to manage meals, weight recovery, and coaching them to return to normal behaviours… all the stuff I help parents with on this website, and that forms part of standard eating-disorder treatment.

Encephalitis: Inflammation of the brain

Very rarely, what looks like an eating disorder might be encephalitis, which means inflammation of the brain. Inflammation occurs usually as a defence against an infection from pathogens: bacteria (such as strep), viruses (such as mono), parasites or fungi. The inflammation may be autoimmune:  antibodies attack not just pathogens but also brain tissues, leading to the neurological and/or psychiatric symptoms I’m about to describe.

Inflammatory brain disease is rare

Beware of ‘Dr Google’. If I looked up testicular cancer I could be convinced I have it, even with an absence of testicles.

The trusted eating-disorder specialists I consulted for this piece were concerned that readers might set off on an exhausting, time-wasting search for remedies. They have never, or rarely, seen inflammatory brain disease in their eating-disorder patients.

I am treading a fine line between raising your awareness of a possibility, and alarming you.

If you see many indicators of the disease, do raise this with the clinicians. But please don’t let this slow down normal eating-disorder treatment, and please listen carefully to your clinicians. Just because you googled PANS or PANDAS does not make you more expert than they are.

I myself have no expertise on the topic: I am merely collating information gathered from other sources. I don’t have the expertise to assess how trustworthy these sources are.

I do know what eating disorders tend to look like. So whereas websites on brain inflammation list symptoms that you may recognise in your child, on this page I tell you which are part of a bog-standard eating disorder.

Classification and acronyms

I’m using the umbrella terms ‘encephalitis’ or ‘inflammatory brain disease’ or ‘brain inflammation’ for these categories used in research or by advocacy groups:

  • BGE: ‘inflammatory’ or ‘post-infectious’ Basal Ganglia Encephalitis. BGE is thought to be a form of ‘Autoimmune Encephalitis (AE)’.
  • PANS: ‘Pediatric Acute-onset Neuropsychiatric Syndrome’. It groups neurological disorders suspected to originate from infection in the basal ganglia, so PANS is a subset of BGE.
  • PANDAS: ‘Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections’. PANDAS are a subset of PANS. There must be a strep (streptococcal) infection, often this is a Group A Strep (GAS) infection. The gut microbiota may be abnormal too.

When a child has neuropsychiatric symptoms following an infection or other trigger, this may be labelled as CANS: Childhood Acute Neuropsychiatric Syndrome. Some use CPAE: Children Pediatric Autoimmune Encephalopathy.


Different groups of symptoms lead to different classifications, and this is all for research purposes, as there is no diagnostic test. For simplicity I’ll lump all the symptoms together here.

Major criteria that flag up the possibility of brain inflammation:

  • Eating restriction and/or:
  • Obsessive-compulsive symptoms (OCD)

I’ll say more about these in a minute. They are common in any eating disorder, but this next major criterion is not:

  • tics or other motor abnormalities: you might see with a big deterioration in handwriting (google ‘PANS and handwriting’ to see examples) or in their ability to do a craft, or in the way your child moves (including a type of jerkiness or involuntary movement called ‘chorea’)

For brain inflammation one would also expect some of the following.

I’m going to start with those that are not very common in standard eating disorders, so that you flag them up to your treatment team:

  • enuresis (urinary incontinence, bed wetting) or increased urinary frequency
  • transient visual or auditory hallucinations (as part of  OCD) [Silverman et al, 2019]
  • pupils being enlarged
  • the onset is acute, sudden or dramatic (but note that with ordinary malnutrition, young children deteriorate fast anyway)

And now onto signs that are quite common in ordinary eating disorders too

(They would only be signs of brain inflammation if they were extreme, and in combination with other signs):

  • deterioration in school performance, difficulties with maths, inattentive, distractible, unable to focus, increase in hyperactivity, difficulties with memory and concentration, brain fog, regression to baby talk
  • sensory abnormalities such as becoming super-sensitive to certain tastes or textures in food, or a sensitivity to smells, sounds, clothes, temperatures or light. And yes, you’ve guessed it, autism and inflammatory brain disease may get confused, or a child may have both.
  • sleep disturbances (restless, nightmares, and during REM sleep, when they should be paralysed, they move)
  • speech can be  affected: stuttering, mutism (selective or not)
  • the first onset is in early childhood and then recurred occasionally

And even more common in ordinary eating disorders:

  • anxiety or panic attacks, over things that previously were no big deal
  • emotional lability (big swings in mood)
  • depression
  • irritability, aggression, personality change, oppositional defiance
  • behavioral or developmental regression (behaving like a much younger child), or separation anxiety (scared of going to school, clinging to a parent, the home, or even their bedroom)
  • recurrence, relapses (relapses are common in eating disorders, especially if stages of treatment were omitted); if the diagnosis of brain inflammation is established, these are referred to as ‘flares’

More on eating restriction: is it an eating disorder or brain inflammation?

Inflammatory brain disease may lead to distress with eating or drinking, and this usually leads to weight loss. So there’s an overlap with anorexia nervosa, atypical anorexia nervosa, or ARFID.

The eating behaviours described in those with inflammatory brain disease look to me to be the same as in a standard eating disorder: there’s distress, avoidance, aggression, ‘picky’ eating, rituals, gagging and spitting saliva or spitting out food.

So don’t jump to the conclusion that your child has brain inflammation just because they have bizarre behaviours around eating.

Note also that the criteria for inflammatory brain disease can become so wide that they become contradictory. I worry that we can make anything fit once we decide our child might have PANS. For instance, eating restriction is a major criterion… or not: Stanford has been studying kids “meeting criteria for PANS” yet only 47 percent had eating restriction at initial presentation. There may even be excessive eating.

More on OCD: is it a sign of an eating disorder or brain inflammation?

There is a strong genetic correlation between anorexia and OCD, so we should not suspect brain inflammation just because someone has both. Even people who do not have OCD can exhibit (possibly dramatic) OCD-type behaviours and thoughts while malnourished. These include:

  • rituals around food
  • fidgety, cannot stay still, movement or exercise compulsion – though careful: exercise or movement compulsion is extremely common in an ordinary eating disorder
  • ADHD-like symptoms (Attention Deficit and Hyperactivity Disorder) – though careful: there is an overlap between ordinary eating disorders and ADHD
  • anxieties around hygiene, such as repeated handwashing (or conversely, a fear that water will make you fat)
  • distress at eating food deemed contaminated
  • a repeated need to spit, gagging (sometimes from a belief that saliva will make you fat)
  • fear of vomiting (emotophobia)
  • an anxious need to arrange objects in a particular neat position
  • a compulsion to repeatedly do, say or ask the same thing

As people get renourished, some of these aspects subside, but with an eating disorder it’s also normal for some to persist for many more months.

Now for some signs of inflammatory brain disease that to my knowledge are not very common in ordinary anorexia nervosa or ARFID. If your child has them I suggest you flag them up to your clinical team:

Could it be brain inflammation even without the OCD?

Dr Cynthia Kapphahn describes here how all the patients she’s seen who were likely to have PANS also had OCD. None just had eating issues. But she also makes the point that the OCD may be hard to detect if, for instance, it takes the form of intrusive thoughts.

Again, notice how the symptoms can be so wide that we parents could easily jump to conclusions.

What about distress around body shape / weight and PANS?

Distress around weight, and body image disruption, neither exclude or corroborate a diagnosis of PANS/PANDAS. Some PANS patients have it, some don’t [Toufexis et al. 2015, and more here on this talk by Dr Kapphahn].

How is brain inflammation, PANS or PANDAS diagnosed?

There is no absolute diagnostic test. You need a clinician who can look at the whole picture, so your job is to list what you observe.

For diagnostic criteria there is a flowchart here on the pandasppn website and also a list on the International OCD Foundation

Lab tests may include blood tests for antibodies and cultures from swabs. Of note, strep can be found in areas of the body other than just the throat, so a negative throat swab does not necessarily mean the child does not have a strep infection.

Lab tests only form part of the diagnosis: “’negative’ lab values to not rule out PANS while ‘positive’ lab values do not rule PANS or PANDAS in”. According to the International OCD Foundation, “If test results are all normal, it does not rule out a diagnosis of PANS, and exposure to infections from close contacts should be considered.” A clinician will also do a physical examination to look for signs of pathogens and for signs of ‘chorea’: motor issues, tics, joint pain, rheumatologic signs.

Of great importance is a detailed history of the child’s symptoms and behaviours, and of illnesses in the family [for instance Dr Andrew Baumel in this 2021 conference]. So parents, draw up a timeline ahead of your visit to a clinician, noting infections, rheumatologic disorders and autoimmune disorders in other family members. Think of sore throats, tender lymph nodes, tonsil issues, abdominal pain, vomiting, redness around the anus or vagina.

Again, notice how the criteria can be so wide-ranging (an infection might have arisen in any family member at any time in the past, and lab tests can be interpreted either way) that you could easily convince yourself that your child has inflammatory brain disease when there are more straightforward explanations.

Can the GP/pediatrician assess or will I need a specialist?

If you have an eating disorder team, they should have the expertise to refer you to the appropriate specialist. If you don’t have a team, take your concerns to your general practitioner. Pediatrician Dr Andrew Baumel explains, in this 2021 conference, how a generalist can treat many mild to moderate cases.

If you think your child might have PANS and the clinicians are telling you this is not the case, even after reviewing your report on symptoms and history, what can you do? You can ask for a second opinion –you are after all your child’s advocate. On the other hand, be ready to accept that you are wrong. Anorexia nervosa and ARFID are seriously weird illnesses in their own right, and yet they are treatable. So keep doing the eating-disorder treatment.

If eating-disorder treatment is not working then it’s the clinicians’ job to review what more can be done. They may still be certain your child does not suffer from PANS and that it would be wrong to engage in a drug treatment with side-effects. But they should keep looking for avenues that will bring your child to recovery. For instance, they might bring forward how they address OCD or anxiety or trauma or autism.

Stories of children with PANS

Personal stories may ‘speak’ to you more than a list of symptoms. Here are some examples:

“My daughter had the sudden onset urinary frequency that is a hallmark sign for many PANDAS/PANS kids. Literally overnight. It was awful. Then came the anxiety, OCD, intrusive thoughts, insomnia and finally the eating disorder with exercise compulsion […] Strep was a major issue for her when she was young.” (from the Around The Dinner Table forum)

Dr Kapphahn describes a couple of children here on YouTube (‘those patients you’ll never forget’).

And there are some vivid stories on the Neuroimmune site here.

But eating disorders are bizarre anyway

Listen to your clinicians if they tell you that your child’s symptoms are typical of a standard eating disorder and that it’s ‘just’ a question of continuing the hard work of standard treatment.

For instance, here is a 10-year old, in malnutrition, awaiting eating disorder treatment. She is super-anxious about anyone touching her food (partly a heightened anxiety about hygiene, partly because fingers might add some fat). She is resists having a shower, drinking fluids, and even swallowing her own saliva as she believes these will make her fat). She has moments of distress and aggression where she is sure her mother is not her mother. Sitting – especially during car journeys – is agony: she hovers over the seat. As with most youngsters with anorexia, these bizarre and distressing symptoms subside with nourishment and weight gain.

For more information

I have drawn on the sources below to write this page:

Thank you

I am super grateful to a fellow parent for educating me about this issue, to the extent of paying a large amount to get me access to the 2021 online conference I refer to here, all so that more parents get the information they need.

And I was really glad to have a couple of trusted eating disorder specialists suggest some changes to this page. I am not naming them because I want to keep emphasizing that this field is evolving and you should trust your own clinicians more than you trust this page.