BROOKLYN, N.Y.– Children who develop an obsessive-compulsive disorder with a dramatically acute onset might have a newly described condition known as Pediatric Acute-Onset Neuropsychiatric Syndrome.

The syndrome is so new that a U.S.-based expert panel, the Pediatric Acute Onset Neuropsychiatric Syndrome (PANS) Consensus Conference, met in May 2013 to devise the first recommendations for the clinical assessment of children with suspected PANS. A report was released last October ( J. Child Adolesc. Psycharmacol. 2014 [doi:1089/cap.2014.0084] ).

“The key issue is the acute onset,” Dr. Barbara J. Coffey said at a psychopharmacology update held by the American Academy of Child and Adolescent Psychiatry. “Typical obsessive-compulsive disorder (OCD) is not dramatic in onset in kids, but with PANS, which will probably involve 10% or less of all children with OCD, these kids are perfectly fine and developing normally and then one day they suddenly won’t go to school, won’t touch anything, won’t eat, and look terror stricken,” said Dr. Coffey, professor of psychiatry and chief of the Tics and Tourette’s Clinical and Research Program at Mount Sinai Hospital in New York.

PANS as a diagnostic entity traces its roots back to Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS), first described in 1998 by Dr. Susan E. Swedo and her associates at the National Institute of Mental Health ( Am. J. Psychiatry 1998;155:264-71 ). PANDAS more recently “morphed” into PANS as research identified potential infectious triggers beyond group A streptococcus as well as noninfectious environmental or metabolic factors that could trigger an acute-onset OCD similar to PANDAS, Dr. Coffey said.

The new PANS diagnostic criteria recommended by the 2013 consensus panel defined the syndrome as an “abrupt, dramatic onset of OCD or severely restricted food intake with at least two additional, concurrent neuropsychiatric symptoms, also with acute onset, from this list: anxiety; emotional lability, depression, or both; irritability, aggression, or severe oppositional behavior or some combination of these; behavioral regression; deterioration in school performance; sensory or motor abnormalities; and somatic signs or symptoms, including sleep disturbance, enuresis, or urinary frequency.

Another key diagnostic touchstone is that the symptoms cannot be explained by another neurologic or medical disorder, which means workup of a child with suspected PANS must be comprehensive and must rule out other plausible causes. “PANS is a disorder of exclusion; you need to rule out everything else,” Dr. Coffey said. The differential diagnosis includes OCD, anorexia nervosa, avoidant /restrictive food intake disorder, Tourette syndrome, transient tic disorder, bipolar disorder, Sydenham’s chorea, autoimmune encephalitis, systemic autoimmune disease, and Wilson’s disease.

A recent report from researchers at the University of South Florida in Tampa presented findings from a study of 43 children aged 4-14 years, diagnosed with PANS, who presented with more than 40 clinical symptoms ranging from anxiety and mood and behavioral symptoms in all patients to features such as sleep disturbance, tics, urinary problems, and attention-deficit/hyperactivity disorder ( J. Child Adolesc. Psychopharmacol. 2014 [doi:10.1089/cap.2014.0062] ). “What is remarkable to me is that literally every psychiatric symptoms known is listed,” Dr. Coffey said. “It is a challenge to work your way through these.”

The consensus group recommended that workup of a child with suspected PANS should include a family history, medical history, physical examination, psychiatric evaluation, infectious diseases evaluation, neurological assessment, assessment of symptoms and history to gauge possible immune dysfunction, assessment of somatic symptoms, and genetic evaluation.

The Tampa study of 43 PANS cases documented a long list of apparent triggers, including several types of infection as well as immune disorders such as Kawasaki’s disease, allergies, and asthma. Among the infections implicated as triggers, group A streptococcus remained the most frequent, in 58% of cases, but other apparent triggers included Mycoplasma pneumoniae, in 12%, and an upper respiratory infection in 37%.

When an infection is the suspected trigger, management includes antibiotic treatment to eradicate the pathogen, usually with a penicillin or a cephalosporin, but azithromycin can be helpful because of its efficacy against Mycoplasma. Treatment usually needs to continue for 4-6 weeks, and in many cases much longer. Management also should include clinical treatments for psychiatric manifestations, such as for OCD, Dr. Coffey said.

Dr. Coffey has served on advisory boards for Eli Lilly, Jazz, and Novartis, has been a speaker on behalf of Quintiles, and has received research grants from Boehringer Ingelheim, Bristol-Myers Squibb, Catalyst, Eli Lilly, Otsuka, and Shire.

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