Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infection (PANDAS)

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infection (PANDAS) is the presence of Obsessive-Compulsive Disorder (OCD) and/or tic disorder at prepubertal age of onset with abrupt onset and relapsing-remitting symptom course. The defining features are a temporal association between symptom exacerbations and a Group-A beta-hemolytic streptococcal (GAS) infection. There are also neurological abnormalities during exacerbations (adventitious movements or motoric hyperactivity). PANDAS remains a somewhat controversial diagnosis.^[1]

The NIMH Criteria (2004) propose the following:^[2]

1. OCD or tic disorder
2. Onset: age 3 to puberty
3. Abrupt onset or exacerbating course
4. Strep infection leading to onset/exacerbation of symptoms
5. Neurological abnormalities

Pediatric acute-onset neuropsychiatric syndrome (PANS) is a condition defined by sudden onset of obsessive-compulsive symptoms and/or severe eating restrictions, along with at least two other cognitive, behavioural, or neurological symptoms. This diagnostic construct allows for identification of cases without clear evidence of autoimmune process, and is not restricted to streptococcal infection:^[3]

1. Abrupt, dramatic onset of OCD or anorexia
2. Concurrent presence of 2 or more additional neuropsychiatric symptoms with similarly severe and acute onset. These include:
   • Anxiety
   • Mood swings and depression
   • Aggression
   • Irritability and oppositional behaviors
   • Developmental regression
   • Sudden deterioration in school performance or learning abilities
   • Sensory and motor abnormalities
   • Somatic signs and symptoms
3. Symptoms are unexplainable by a known neurologic or medical disorder

Unfortunately, detailed and consensus recommendations for the treatment of PANDAS remain lacking, and various treatments have been used (but have high risk for bias).^[4] Some general treatment principles include:

• Any acute streptococcal infection should be treated with antibiotics.
• However, elevated strep titers only indicate that a patient has had strep exposure; it is unable to indicate when the strep infection occurred. Thus, children may have continue to have “positive” titers for many months after a single infection.
• Prophylactic antibiotic use post-acute infection has been shown to be useful in one study, but this randomized control trial lacked a non-placebo control group.^[5]
• Patients can benefit from cognitive behavioural therapy (CBT) at any point as it is a minimally invasive treatment approach.^[6]
• Selective serotonin reuptake inhibitors (SSRIs) may be indicated in more severe cases.

• NIMH: PANDAS—Questions and Answers

• Orlovska, S., Vestergaard, C. H., Bech, B. H., Nordentoft, M., Vestergaard, M., & Benros, M. E. (2017). Association of Streptococcal Throat Infection With Mental Disorders: Testing Key Aspects of the PANDAS Hypothesis in a Nationwide Study. JAMA psychiatry.
• Wilbur, C., Bitnun, A., Kronenberg, S., Laxer, R. M., Levy, D. M., Logan, W. J., ... & Yeh, E. A. (2019). PANDAS/PANS in childhood: Controversies and evidence. Paediatrics & child health, 24(2), 85-91.