PANDAS
These criteria describe a neuropsychiatric syndrome with the presence of obsessive-compulsive behaviours or tics, with onset triggered by a group A streptococcal (GAS) infection. 

PANDAS can be diagnosed when all of the five criteria are present. 

The PANDAS diagnostic criteria:

I. Presence of obsessive-compulsive behaviours or tics*
II. Prepubertal symptom onset (symptoms must appear before puberty starts, which can be different for each child)
III. Acute symptom onset and episodic course (symptoms come and go, or ‘flare’, when exposed to a trigger)
IIIV. Temporal association between Group A streptococcal infection and symptom onset/exacerbations (There must be a link which shows evidence of a strep A infection and symptoms of PANDAS beginning, or worsening in the case of young people who already have a diagnosis of PANDAS)
V. Association with neurological symptoms (such as an increased level of movement such as fidgeting/difficulty remaining seated and involuntary, random movements).

*The crucial difference between typical OCD and the obsessive-compulsive behaviours seen in cases of PANDAS is the sudden onset of the latter. This abrupt onset is in stark contrast to the gradual development of obsessions-compulsions experienced by children with childhood OCD, rather than PANDAS [2-5]. 

PANS

The PANS criteria describe a clinically distinct presentation, which includes the abrupt onset* (< 3 months) of obsessive-compulsive behaviours or a severely restricted food intake (tic disorder is not required) with a concurrent development or exacerbation of other neuropsychiatric symptoms [5, 6, 8]. PANS is triggered by preceding infections that are not limited to GAS [6, 7]. Other known medical diseases should be ruled out before a diagnosis of PANS is reached; hence PANS is a diagnosis of exclusion. 

The PANS diagnostic criteria. There is no age limit. 

I.Abrupt, dramatic onset of obsessive-compulsive disorder or severely restricted food intake.
II. Concurrent presence of additional neuropsychiatric symptoms, (with similarly severe and acute onset), from at least two of the following seven categories:
    1. Anxiety
    2. Emotional lability and/or depression
    3. Irritability, aggression, and/or severely oppositional behaviours
    4. Behavioural (developmental) regression
    5. Deterioration in school performance (related to ADHD-like symptoms, memory deficits, cognitive changes, etc.)
    6. Sensory or motor abnormalities
    7. Somatic signs and symptoms, including sleep disturbances, enuresis, or urinary frequency
III. Symptoms are not better explained by a known neurologic or medical disorder, such as Sydenham’s Chorea. 

The individual PANS symptoms overlap with a variety of psychiatric disorders, such as OCD, Tourette’s Syndrome, ADHD, depression, bipolar disorder, schizophrenia and lupus cerebritis; as well as Autism, ODD or sensory processing disorder [6, 12-16]. 

However, it is the acuity of onset – or acute exacerbation of – and simultaneous presentation of symptoms in multiple domains that differentiate PANS from these psychiatric conditions [6]. 

The symptom profiles of patients with PANS often have a “relapsing/remitting” course with rapid progression to maximum symptom severity and rapid return to previous function over hours or days [17]. Some patients present with a chronic-static/progressive course [18]. 

Many children with PANS are extremely ill, with extreme compulsions (licking shoes, barking), motor and phonic tics, behavioural regression, hallucinations, separation anxiety (often associated with obsessional thoughts about a parent’s death) and terrifying episodes of extreme anxiety or aggression [6, 9]. Some children display severe psychotic symptoms [10, 11]. The behavioural manifestations often prompt rapid referral to psychological or psychiatric services, but all patients should receive a full medical evaluation. 

Successfully established multidisciplinary PANS and PANDAS clinics and teams, their assessment protocols and outcomes have been documented by specialist clinics in Stockholm [18, 22-24], Gothenburg [25], Stanford [10, 26-28], Florida [2], Genoa [29], Florence [30] and Rome [31, 32]. 

Recommended investigations and test panels to support clinicians in the identification and management of PANS and PANDAS patients have been described [6, 29, 33]. In the light of increasing evidence for secondary immune-mediated forms of OCD, the Immuno-Neuropsychiatry Group of the European College of Neuropsychopharmacology (ECNP), have produced a first proposal of clinical criteria for the definition of secondary autoimmune OCD – including PANS and PANDAS – and its clinical investigation [5]. 

The national PANS PANDAS Steering Group (PPSG) has been created with representation from relevant medical royal colleges and other stakeholders to address the variation in care available to children and young people presenting with symptoms of PANS and PANDAS in the UK 

 A subgroup of the PPSG is the UK Clinical Guideline Development Group which is in the process of developing a UK treatment guideline for PANS and PANDAS. The guideline, which is anticipated to be published in late 2026, will help to end the current variation in the diagnosis and management of people presenting with symptoms of PANS and PANDAS in the UK. The PPSG recommends that clinicians be aware of existing international peer-reviewed guidelines until UK national treatment guidelines are published. 

International guidelines: 

1. PANS research consortium treatment guidelines 

The PANS research consortium guidelines, published in 2017, represent a collective standard of care and best evidenced treatment guidelines for PANS and PANDAS [34-36]. An overview of these treatment guidelines is available [37]. 

Development of these guidelines was undertaken by three workgroups of the PANS and PANDAS Clinical Research Consortium. They separately addressed 1) use of psychiatric medications and behavioural interventions; 2) use of antimicrobials; and 3) use of anti-inflammatory and immunomodulating therapies. Each workgroup first reviewed the published literature and then drew upon their combined clinical experience with more than 1,000 children with PANS or PANDAS to formulate an initial set of recommendations, which were then sent to a separate group of expert clinicians for critical review and comment [37, 38]. 

The resulting peer-reviewed and published PANS Research consortium guidelines were contributed to by 44 named contributors representing 23 highly respected academic institutions from across the US, Canada and Australia. These included not only clinicians with expertise in the diagnosis and treatment of PANS and PANDAS, but also experts in the fields of child psychiatry, paediatrics, infectious diseases, microbiology, neurology, neuroimmunology, immunology and rheumatology. As such, the PANS Research consortium treatment guidelines represent recommendations from a multidisciplinary and responsible body of clinicians with experience in appropriately treating patients with PANS and PANDAS. 

The PANDAS Physicians Network, an inter-disciplinary group with expertise in the medical sub-specialties that are relevant to PANS and PANDAS who include the contributors to the PANS Research consortium guidelines, provide evidenced information on the treatment of PANS/PANDAS via their website – including a treatment flowchart www.pandasppn.org/flowchart/ 

2. Nordic Guidelines 

Clinical guidance for diagnosis and management of PANS in the Nordic Countries – Click here 

In 2021 a Nordic-UK working group published peer-reviewed clinical guidelines for the diagnosis and management of suspected PANS in the Nordic countries. These guidelines, co-authored by British Paediatric Neurology Association members, recommend a comprehensive medical history work-up which includes symptom assessment related to infectious, autoimmune and rheumatic diseases as well as psychiatric, neurologic and neurodevelopmental diseases. The treatment aims outlined in the Nordic countries’ guidelines are threefold: treating ongoing verified infections, suspected inflammation and mental health symptoms. 

A detailed review of patients seen by the Stanford Immune Behavioural Health/PANS Clinic [28] has shown that PANS children are more sensitive to the side effects of psychiatric medications than in children with other, non-PANS, diagnoses (OCD, anxiety, depression, and aggression), and that adverse reactions to SSRIs can occur in a large proportion of PANS children if normal doses are used, particularly in the first instance. Paradoxical response to psychotropic medications may be an indication that a PANS diagnosis requires consideration [9, 40, 41]. 

Estimation of the actual prevalence of PANS and PANDAS is not well described and this is complicated by inconsistencies of inclusion criteria and methodologies in various studies [19, 20]. With epidemiological data of related conditions such as Tourette’s Disorder and OCD finding that 0.3%-3% of children are affected with these conditions, it follows that a smaller subset may then fulfil criteria for PANDAS [21, 19]. 

With the backing of NHS England, the PANS PANDAS Steering Group are embarking on work to roll out a nationwide surveillance study, designed to identify the number of children and young people presenting to healthcare professionals with symptoms matching the diagnostic criteria for PANS and PANDAS.