PANS most often refers to Pediatric Acute-onset Neuropsychiatric Syndrome , a medical condition in children and teens where serious mental health symptoms begin very suddenly, almost “overnight.”

What PANS Is

  • PANS is a clinical syndrome marked by the abrupt onset of obsessive-compulsive symptoms and/or severe eating restriction in a child or adolescent.
  • At the same time, the child develops at least two other neurological, cognitive, or behavioral symptoms, such as anxiety, mood changes, or sleep problems.

Key Symptoms

Common symptom areas include:

  • Obsessive-compulsive behaviors (OCD) or sudden food refusal/restriction.
  • Anxiety, especially separation anxiety or intense fears.
  • Sudden mood swings, irritability, aggression, or depression.
  • Motor or sensory changes, like tics or sensitivity to light, sound, or touch.
  • Regression in behavior (acting much younger) or drop in school performance.
  • Sleep disturbances or new urinary issues (frequency, accidents).

What Causes It

  • PANS is thought to result from a misdirected immune response that affects the brain, often described as “encephalitic-like” (brain inflammation–type) in its presentation.
  • Triggers can include infections, metabolic issues, or other inflammatory processes; when specifically linked to strep infections, it is called PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus).

Course Over Time

  • Symptoms usually begin suddenly, then follow a relapsing–remitting pattern, where they flare up and partially improve over time.
  • Recurrences can be triggered by new infections or immune stressors, and each episode may bring back old symptoms or introduce new ones.

Important Note

If you suspect PANS in a child or teen—especially a very sudden onset of OCD- like behaviors, tics, or extreme eating changes—it is important to seek evaluation from a pediatrician, child psychiatrist, or a clinician familiar with PANS/PANDAS, because early assessment and treatment can improve outcomes.