Is it PANDAS? How to confirm the sore throat/OCD connection
Antibiotics are indicated in only a minority of cases.
- For milder cases with recent onset, begin with clinical monitoring for GABHS, without using SSRIs or antibiotics. Early CBT may prevent symptom worsening.
- For more severecases of longer duration, continue with CBT, then consider adding an SSRI.
Immunomodulatory therapies? Immunomodulatory therapies such as IV immunoglobulin (IVIG) and plasma exchange are not appropriate for refractory OCD or tic cases that have no clear GABHS association and a relapsing/remitting course. No studies support using immunomodulatory agents in disorders without an immune-mediated cause.
You might consider these therapies for severe, clearly established PANDAS only when less-invasive treatments (antibiotics, standard OCD therapies) have been ineffective and then only under research protocols and by physicians experienced in giving them.
Immunomodulatory therapies interrupt autoantibodies’ actions on the CNS and have shown moderate (40% to 50%) symptom reduction in some CNS diseases. In the NIMH trial, plasma exchange was better tolerated than IVIG and provided greater symptom relief.22 However, at least one study has shown plasma exchange to be ineffective for chronic OCD.23
USING ANTIBIOTICS FOR PANDAS
Snider and Swedo24 recommend guidelines for treating PANDAS, based on risks of using antibiotics in children, research and clinical experience, and American Academy of Child and Adolescent Psychiatry practice parameters (Box 2).
Elevated streptococcal titers are common in the community population25 and are not necessarily diagnostic of PANDAS. Thus, it is important to demonstrate a change in titer levels (such as a 4-fold dilution rise in antistreptococcal antibody titers 4 to 6 weeks after infection).
In patients with new-onset OCD/tics or recent symptom exacerbation, a positive throat culture provides support that symptoms were triggered by subclinical GABHS infection but does not rule out the possibility that the child is a GABHS carrier.
After streptococcal infections, titers may remain elevated for 6 months to 1 year. Murphy et al25 found persistent elevations in one or more strep titers in patients with dramatically fluctuating neuropsychiatric symptoms, compared with those whose course was inconsistent with PANDAS. It is unclear if these children had undetected, frequent GABHS infections or the elevated titers reflect a chronic immune activation to GABHS.
Assess for GABHS infectionin young children with abrupt-onset, obsessive-compulsive/tic-like behaviors (suspected PANDAS), using a 48-hour throat culture. If positive, promptly give a 10-day course of antibiotics effective for acute GABHS treatment (penicillins, cephalosporins, azithromycin).
Attempt to documenta preceding GABHS infection if neuropsychiatric symptoms began abruptly 4 to 6 weeks ago. Perform a 48-hour throat culture and a blood test for antistreptococcal antibody titers (ASO and anti-DNaseB). Do not give antibiotics unless GABHS culture is positive.
A rising titer 4 to 6 weeks later would suggest a recent infection. A single elevated titer does not adequately support a recent strep infection, as some individuals have elevated titers 6 months or longer after GABHS infection.
Consider prospective assessmentfor GABHS infections in children with episodic symptoms. Obtain throat cultures when neuropsychiatric symptoms return/exacerbate, as even untreated strep infections are usually self-limited.
Reserve antibiotic prophylaxisfor use under research protocols and based on solid evidence of PANDAS diagnosis.
Use immunomodulatory therapiesunder research protocols and only for children with acute, severe symptoms who fit the PANDAS designation.
Source: Reference 24.
- National Institute of Mental Health. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS).https://intramural.nimh.nih.gov/pdn/web.htm.
- Murphy TK, Herbstman, DM, Edge PJ. Infectious trigger in obsessive compulsive and tic disorders. In: Fatemi SH (ed). Infectious etiologies of neuropsychiatric disorders. New York: Taylor & Francis (in press).
- Amoxicillin/potassium clavulanate • Augmentin
- Azithromycin • Zithromax
Michael Larson reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.
Dr. Storch receives grant support from the National Institute of Health and Genentech Inc.
Dr. Murphy receives grant support from the National Institute of Mental Health, Bristol-Myers Squibb Co., and the Tourette Syndrome Association (TSA). She is a speaker for Pfizer, Inc.
