PANDAS May Be Overdiagnosed, Contributing to Overuse of Antibiotics

Paula Moyer, MA

November 02, 2006

November 2, 2006 (San Diego) —The pediatric autoimmune condition known as PANDAS may be overdiagnosed and the overdiagnoses, in turn, may be contributing to the overuse of antibiotics, according to a team of investigators who presented their findings here at the 53rd annual meeting of the American Academy of Child and Adolescent Psychiatry.

PANDAS stands for pediatric autoimmune neuropsychiatric disorders associated with streptococcus, and it is characterized by the acute onset of obsessive-compulsive disorder or tic disorder in a patient who has group A beta-hemolytic streptococcal (GABHS) infection. The study investigators were concerned that the PANDAS diagnosis had been widely adopted in the community without confirmatory scientific evidence, and that antibiotics were being used to treat it without empirical justification.

"Our findings showed that PANDAS may be diagnosed in the community before they have met the diagnostic criteria," said Barbara Coffey, MD, MS, in her presentation. Nearly one third of patients diagnosed with PANDAS in the community may not meet those criteria, she and her colleagues found. Dr. Coffey is an associate professor of psychiatry at New York University in New York City.

The investigative team conducted a retrospective chart review of 176 subjects seen at New York University's Child Study Center. The subjects met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, criteria for obsessive-compulsive disorder, tic disorder, or both. The center used diagnostic criteria for PANDAS that were based on research criteria established in 1998 known as the Swedo criteria for their founder, Susan Swedo, MD, from the National Institute of Mental Health. The Swedo criteria are as follows:

  • presence of obsessive-compulsive disorder, tic disorder, or both;

  • with prepubertal onset;

  • sudden, severe symptom onset and an episodic course characterized by remissions and abrupt exacerbations;

  • a link in time between either the symptom onset or exacerbation and a GABHS infection;

  • adventitious movements or clumsiness.

Among the children in the review, 30 (17.05%) had received a PANDAS diagnosis in the community. However, when the staff at the center applied the Swedo criteria, the PANDAS diagnoses were reduced to 19 (10.9%). Within the original 30, 18 who were diagnosed with PANDAS did not meet the criteria used by Dr. Coffey and her team. The remaining 7 patients who were diagnosed by the staff had not received that diagnosis in the community.

Of the 18 patients with the PANDAS community diagnosis that did not meet the center's criteria, 13 of them (72%) were treated with antibiotics or immunosuppressants. Subjects who got the diagnosis in the community were significantly more likely to be treated with antibiotics or immunosuppressants ( P < .001).

"Is PANDAS overdiagnosed? Yes and no," said Tanya K. Murphy, MD, in a phone interview seeking independent commentary. "A lot of primary care pediatricians have not even heard of it, therefore not looking for it and diagnosing it. Some of the primary care doctors use the criteria of high titers and obsessive-compulsive disorder," she said. Dr. Murphy, who was not involved in the research, is an associate professor and chief of child and adolescent psychiatry and director of the anxiety disorders clinic at the University of Florida in Gainesville.

"The investigators say that 17% received a community diagnosis and 11% received a research center diagnosis," Dr. Murphy said. "That's not a huge discrepancy, but the primary care physicians may use weaker criteria."

The gap reflects the fact that PANDAS still has nebulous criteria that may need more refining, Dr. Murphy pointed out. "I have followed over 100 patients with PANDAS presentations prospectively. Whether the diagnosis is appropriate depends on how long the patients have had the illness."

Dr. Murphy continued, "If you look at the younger age group, probably up to 25% to 30% of those with obsessive-compulsive and tic disorders would meet the PANDAS criteria. If you look at older children, the 11% is probably what I am seeing as well." Sudden onset should cause a suspicion, she said, noting that testing titers can help hone the diagnosis if the titers are high for 2 tests taken 4 to 8 weeks apart.

In children with PANDAS, the standard interventions for obsessive-compulsive and tic disorders are effective, Dr. Murphy said. These consist of cognitive-behavioral therapy, reversal therapy in the case of tic disorders, and pharmacologic therapy.

"Just because they have PANDAS doesn't mean you should withhold established treatments," Dr. Coffey agreed. "Cognitive-behavioral therapy can help prevent a more severe episode in the future."

AACAP 53rd Annual Meeting: Abstract C21. Presented October 26, 2006.

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