Pediatric acute onset neuropsychiatric syndrome is associated with various infections (i.e. Streptococcus, Mycoplasma pneumoniae).

We describe a case of PANS associated with mononucleosis, in a patient with Noonan syndrome.

To report a case of EBV-related PANS.

A 13-year-old patient, diagnosed with Noonan syndrome, was referred to the pediatric unit of our hospital in August 2016 because of aggressive behavior and suicidal ideation. He had no personal or family history of psychiatric disorder. His parents and him denied substance abuse. His symptoms had begun abruptly one month prior to our evaluation, after watching an internet video, and consisted in intrusive thoughts and images associated with mental compulsions. Suicidal thoughts and verbal aggressiveness emerged because he felt overwhelmed by these symptoms.

He was initially treated with sertraline 25 mg, and subsequently switched to aripiprazole because of increased anxiety. Throat cultures and anti-streptolysin titer (ASO) were negative, as well as Ig(M) and Ig(G) antibodies for M. pneumoniae. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were also negative. Epstein–Barr virus Ig(M) and Ig(G) were positive. He continued therapy with aripiprazole 10 mg after hospital discharge with partial benefit.

Epstein–Barr virus infection has been reported to precede various neuropsychological disorders, but to the best of our knowledge, rare cases of PANS following mononucleosis have been described in literature. In our case, psychopharmacological treatment for OCD symptoms was the only treatment performed and led to a partial remission of symptoms.

The authors have not supplied their declaration of competing interest.