Anorexia nervosa or pediatric acute-onset neuropsychiatric syndrome? A case report
IMPACT:
This case report highlights the importance of investigating alternative or co-morbid diagnoses when a patient does not respond as expected to treatment or when symptoms worsen or persist. It explores the lesser-known overlap between features of atypical anorexia nervosa and PANS/PANDAS, emphasizing the need to consider these conditions in children presenting with sudden food restriction and a worsening neuropsychiatric presentation.
SUMMARY
“Anorexia nervosa or pediatric acute-onset neuropsychiatric syndrome? A case report highlights the importance of distinguishing atypical anorexia nervosa from Pediatric Acute-onset Neuropsychiatric Syndrome (PANS). In this report, a 9 year old girl developed sudden, severe food restriction driven by fear of weight gain and body image disturbance. Although eating and weight improved with nutritional rehabilitation and restoring regular eating patterns, worsening neuropsychiatric deterioration prompted an investigation into possible PANS. Upon a multidisciplinary evaluation at the Immune Behavioral Health Clinic, a PANS diagnosis was made. Given the acute onset and severity of her neuropsychiatric symptoms, along with reports of intermittent sore throats lasting one to two days, a PCR test was performed and a Group A Streptococcus infection was identified. Based on the presence of the strep infection at the time of symptom onset, it was determined that the patient also met the criteria for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS).
Treatment for the child included nutritional rehabilitation, behavioral interventions, treatment of the strep infection along with confirming the eradication of infection on subsequent PCR testing, anti-inflammatory medication, psychiatric medication, and cognitive behavioral therapy. While on antibiotic treatment, the family reported improvements in aggression, harm-related statements, handwriting, toileting behaviors, and school attendance.
The authors emphasize that acute-onset restrictive eating accompanied by worsening functional impairment, developmental regression, or persistent neuropsychiatric symptoms despite nutritional restoration may warrant evaluation for possible PANS. They also highlight the importance of reassessing the diagnosis when a patient’s clinical course does not align with expected treatment outcomes and the need to coordinate care across specialties for this patient population.
LINK TO PAPER: https://doi.org/10.1186/s40337-026-01783-8
CITATION
Ruiz Fischer, M.M., Derenne, J.L., Silverman, M.A. et al. Anorexia nervosa or pediatric acute-onset neuropsychiatric syndrome? A case report. J Eat Disord 14, 258 (2026). https://doi.org/10.1186/s40337-026-01783-8