Prevalence of pediatric acute-onset neuropsychiatric syndrome (PANS) in children and adolescents with eating disorders

Background: Pediatric obsessive-compulsive disorder (OCD) and eating disorder symptoms frequently overlap, clouding diagnostic certainty and hypothesized etiologic factors. Pediatric acute-onset neuropsychiatric syndrome (PANS) is defined by abrupt emergence of core obsessive-compulsive behaviours and/or food restriction with concurrent, ancillary cognitive and behavioral symptoms. Inflammatory and immune processes have putative roles in both PANS and a related described condition with cardinal obsessive-compulsive or tic symptoms, known as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). While prevalence of PANS and PANDAS has been examined in tic, movement disorder and OCD populations, this has not yet been systematically examined in a pediatric eating disorder sample. Objectives: To identify the lifetime prevalence of those meeting PANS and/or PANDAS criteria within a pediatric eating disorder cohort. Methods: Convenience sampling method was utilized to select consecutive youth (ages 8-18-years) presenting to an interdisciplinary pediatric eating disorder subspecialty program with a confirmed eating disorder and completed parent-report PANS/PANDAS questionnaire (n = 100). A parent-reported measure was used to establish lifetime prevalence rates for PANS and PANDAS. Descriptive and exploratory comparative analyses were conducted between PANS and non-PANS groups. Continuous measures were analyzed using two-tailed independent sample t-tests and categorical measures were analyzed using two-tailed Fisher's exact tests. Results: Among participants, 52% (n = 52) met PANS criteria and 0% (n = 0) met PANDAS diagnostic criteria. Core, abrupt-onset PANS symptoms included both food restriction and obsessive-compulsive symptoms in 63.5% (n = 33), food restriction only in 25% (n = 13), and obsessive-compulsive symptoms only in 11.5% (n = 6) of participants. In comparison to those who did not meet PANS criteria, those in the PANS subgroup were less likely to be male and more commonly prescribed a selective serotonin reuptake inhibitor medication. Significant group differences did not emerge for onset age, body mass index, eating disorder type or comorbid psychiatric/medical/autoimmune illness. Conclusion: Lifetime prevalence of symptoms in keeping with PANS diagnostic criteria within a pediatric eating disorder cohort was notably higher than that previously reported in OCD or tic disorder cohorts. The overlap between starvation effects and ancillary PANS symptoms may challenge the practical utility of this putative syndrome within the eating disorder population.