When Infection Triggers OCD: PANDAS / PANS

PANDAS / PANS. Getty Images

In 1998, Dr. Susan Swedo and colleagues, investigators at the National Institute of Mental Health, first described in the scientific literature a subtype of obsessive compulsive disorder (OCD) in which children demonstrate an unusually abrupt onset of OCD and other neuropsychiatric symptoms (e.g., tics, incapacitating anxiety, irritability, mood swings, hyperactivity, handwriting changes) preceded by streptococcal infection.

Once the strep is successfully treated, the neuropsychiatric symptoms largely abate until a recurrence of infection, thus, occurring in a relapsing-remitting, “saw-toothed” pattern.

In the early 1990s, Dr. Swedo and colleagues had been studying Sydenham’s Chorea (SC), which can result from strep infection, finding that 70% of individuals diagnosed with this movement disorder exhibit acute-onset OCD. Investigators hypothesized that the cross-reactive antibodies which trigger the problematic immune system response in SC, may, in some cases, cause OCD and other neuropsychiatric symptoms, without the complication of SC symptoms. This syndrome was termed PANDAS, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections. In PANDAS, the body’s immune system is over-reactive to strep bacteria, leading to psychiatric and neurological symptoms.

There is strong evidence to support the immune system’s over-reactivity to various bacterial infections, resulting in the exhibition of neurological and behavioral symptoms.

However, what exactly triggers symptoms in this subset of children remains unclear and may extend beyond group A streptococci to other infectious agents (e.g., lyme, mycoplasma, mononucleosis, flu), and environmental or metabolic factors.


In 2012, this syndrome’s description was expanded to include these other potential triggers and has been named PANS, Pediatric Acute-onset Neuropsychiatric Syndrome.

Proposed diagnostic criteria include:

  • Abrupt, dramatic onset of OCD or severely restricted food intake
  • Concurrent presence of additional neuropsychiatric symptoms, with similarly severe and acute onset, from at least two of the following:
  • Anxiety
  • Emotional lability and/or depression
  • Irritability, aggression, and/or severe oppositional behaviors
  • Behavioral (developmental) regression
  • Deterioration in school performance
  • Sensory or motor abnormalities
  • Somatic signs and symptoms, including sleep disturbances, enuresis, or urinary frequency
  • Symptoms are not better explained by a known neurological or medical disorder, such as Sydenham chorea, systematic lupus erythematosus, Tourette’s disorder or others

PANDAS/PANS has an acute onset, typically increasing from initial symptom onset to severe impairment in 24 to 48 hours. The course is relapsing-remitting, with significant interepisodic reduction of symptoms (or, sometimes complete resolution). Studies suggest that PANDAS/PANS occurs more frequently in boys (2:1). Most children affected by this disorder experience symptoms by 8 years of age.

Antibiotics to treat active strep infection are prescribed. Some physicians also prescribe long-term prophylactic antibiotics to decrease the likelihood of significant recurrent infections and the neuropsychiatric symptoms that follow.

Current evidence-based symptom treatments typically involve cognitive behavioral therapy [Exposure and Response Prevention (ERP/ExRP) for OCD, Habit Reversal Training (HRT)/Comprehensive Behavioral Intervention for Tics (CBIT)] and medication (selective serotonin reuptake inhibitors for OCD and anti-dopaminergic agents for tics).

For more information about OCD and PANDAS/PANS, visit the International OCD Foundation at www.iocdf.org.


Swedo SE et al., "Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections: Clinical Description of the First 50 Cases", Am J Psychiatry 155:2, February 1998. http://ajp.psychiatryonline.org/cgi/reprint/155/2/264

Swedo, SE et al., “From Research Subgroup to Clinical Syndrome: Modifying the PANDAS Criteria to Describe PANS (Pediatric Acute-Onset Neuropsychiatric Syndrome)”, Pediatr Therapeut 2:2, 2012.

Storch EA, Murphy TK, Geffken, G et al, "Cognitive-Behavioral Therapy for PANDAS-Related Obsessive-Compulsive Disorder: Findings From a Preliminary Waitlist Controlled Open Trial", Journal of the American Academy of Child & Adolescent Psychiatry: October 2006 - Volume 45 - Issue 10 - pp 1171-1178 http://www.ncbi.nlm.nih.gov/pubmed/17003662

Murphy TK, Storch EA, Strawser MS, "Selective serotonin reuptake inhibitor- induce behavioral activation in the PANDAS subtype", Primary Psychiatry, 2006;13(8):87-89, http://mbldownloads.com/0806PP_Murphy.pdf 

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