PANS is a neuropsychiatric syndrome characterized by the acute onset of obsessive compulsive and other abnormal behaviors, tics, and mood changes that appear in a child following a bacterial or viral infection. PANS refers to any pediatric acute-onset neuropsychiatric syndrome of this type, while PANDAS refers more specifically to such a syndrome that occurs after exposure to streptococcal infections.
New research suggests that treatment with the antibiotic azithromycin can treat PANS. In a study presented at the 2016 meeting of the Society of Biological Psychiatry, Tanya K. Murphy and colleagues found that among 32 children aged 4–14 who showed obsessive compulsive symptoms following an infection, those who were given a 4-week course of azithromycin (10mg/kg of body weight, up to 500 mg/day) saw a 26% drop in symptoms, compared to a 1% drop in symptoms in those who received placebo instead.
At the end of the four weeks, 38.9% of the azithromycin group were classified as much improved or very much improved, while no one in the placebo group achieved this level of improvement. Azithromycin treatment increased the QTc interval (a measure of heart rate) and pulse in the study participants, but did not have any other notable side effects.
PANS is thought to arise from an immune response to infection that goes awry and begins attacking neurons in the brain, particularly in the thalamus. For a more complete review of PANS, see several of our earlier articles about PANS and an excellent review article by researcher Kiki Chang and colleagues in the Journal of Child and Adolescent Psychopharmacology in 2015.
It is important to work up a child suspected of having PANS, as the syndrome does not usually respond to conventional psychiatric treatment and often requires anti-inflammatory drugs (steroids or immunosuppressants), intravenous immunoglobulin (IVIG), plasma exchange, the TNF alpha blocker infliximab, or antibiotics.