PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) and a suggested subset, PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections), are proposed, but to date unsubstantiated, conditions in which a proposed infectious and autoimmune response results in a sudden onset of neuropsychiatric symptoms and functional impairment in a pre-pubertal child. Acute psychiatric symptoms may occur alone or in conjunction with neurologic signs/symptoms and do not exclude other DSM5 diagnoses manifesting similar psychiatric symptoms.