Psychosis is defined as the presence of false beliefs or false perceptions. In children some causes of psychosis include psychiatric diagnosis such as schizophrenia and autism. However, it may also be secondary to medical conditions like various forms of encephalitis. Studies have shown that IVIG has been efficacious in the treatment of psychosis in the setting of autoimmune encephalitis.

A 9-year-old girl with a past medical history of Turner Syndrome, developmental delay, epilepsy, growth hormone deficiency, metabolic bone disease, and autism (ASD) presented with auditory and visual hallucinations that began June 2020. She began with her hearing voices that repeated the word “dead” and told her that she would not live. The hallucination later took the form of a man that would mock her, laugh about her parents dying, and tell her to kill them. The patient had associated symptoms of insomnia, anxiety, sadness, and increased anger. On her initial admission, CSF studies including culture and gram strain were unremarkable. NMDA, VHKC, and GAD65 antibodies were negative. At this time the hallucinations were thought to be due to ASD and she was prescribed Risperdal 0.25mg twice a day. Unfortunately, this did not improve her symptoms and from the time period of June 2020 to May 2021 she subsequently underwent trials of Risperdal, Zyprexa, Invega, Abilify, Thorazine, Haldol, and Clozaril. However, the symptoms persisted. Zoloft was prescribed, which was efficacious for anger and dysphoria. Trazodone, melatonin, and Remeron were tried for the treatment of insomnia, but did not cause enough improvement to continue the medications. Due to progression of command hallucinations with “the man” instructing her to hurt others, the patient was admitted July 2021 for administration of IVIG. Repeat CSF studies and brain MRI were unremarkable. From July 29, 2021 to August 1, 2021 she received three doses of IVIG which resulted in improvement of psychosis. Prior to administration, she was seeing “the man” throughout the day every single day, was sleeping only 3–4 hours a night, and having nightmares everyday. On evaluation 2 weeks after IVIG, she was only seeing “the man” 1–2 time a day, sleeping 6–8 hours a night, having nightmares 1–2 times a week, and her mood had improved.

This case illustrates the potential use of IVIG for the treatment of treatment-resistant psychosis. Although the cause of this patient’s symptoms remains unclear, there were clear benefits from the administration of IVIG that were not seen with trials of antipsychotics.

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