Our patient was a 9-year-old previously healthy girl who presented to the ED with a chief complaint of acute-onset obsessive-compulsive behavior. Eleven days prior to presentation, she became emotionally labile, manifested as sudden episodes of sadness, withdrawal, and unwillingness to participate in social events. Five days prior to admission, her parents observed her displaying ritualistic behaviors such as watching a YouTube commercial 75 times, walking in certain patterns, taking her pajamas on and off a certain amount of times before going to school, picking her lips, and banging her ankles and the side of her abdomen against the kitchen counter. These behaviors would occupy the patient for 4-6 hours, affecting her ability to function normally. She explained that if she did not engage in these behaviors, she would continue to think about them and was worried that something bad may happen to her or her parents. She was also described as having decreased concentration and difficulty performing simple mathematical equations. This was very unusual, as her parents described her as a highly spirited and functional child who is popular at school:participating in advanced math classes, piano, tennis, and gymnastics.
Concerned with her behavior, she was taken to her primary doctor whose workup included Epstein-Barr virus (EBV) serology, anti-deoxyribonuclease (anti-DNase), antistreptolysin O (ASO), thyroid function tests (TFTs), complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid-stimulating hormone/thyroxine (TSH/T4), and Lyme serology (all within normal limits). An impression of PANDAS was made, and she went home on amoxicillin and fluoxetine, which she took for two days prior to her presentation to our ED.
The family considered stress as a possible contributing factor and spent a weekend away from home for a change in environment. In their hotel room, she would ritualize walking back and forth several times. If she failed to complete these rituals, it would result in emotional outbursts and a strong urge to repeat them. Her ability to eat and drink was also impaired, causing her to become dehydrated and prompting her parents to bring her to the ED. This process took five hours due to her extreme reluctance to leave the hotel room before completing her rituals.
Review of systems was significant for the following: constitutional:negative for malaise and weight loss; skin:negative for rash, positive for bruising on ankles and waist; gastrointestinal:negative for vomiting and abdominal pain; neurologic:negative for weakness, neck pain, neck stiffness, paresthesia, and seizures.
Family history was significant for anxiety in both parents. Socially, she was living with her parents with strong support from her grandparents who live nearby. No report of sexual abuse, physical abuse, or bullying at school. Her medications included fluoxetine and amoxicillin that were started two days prior to hospitalization by her pediatrician. Allergies included oseltamivir.
On examination, she appeared well looking, in no apparent distress. Her vitals were normal; central nervous system (CNS):neck supple, pupils equal and round, reactive to light (PEARRL), cranial nerves II-XII intact, motor, sensation, and power normal; Her affect was normal, and her mood was congruent; Head, eyes, ears, nose, and throat (HEENT):mucous membranes dry; skin:healing bruises on her ankles and waist; cardiovascular, respiratory, and abdominal exams were normal.
In the ED, she received maintenance intravenous fluids (IVF) and was admitted to the general pediatrics floor with a presumptive diagnosis of Pediatric Acute-onset Neuropsychiatric Syndrome (PANS).
She continued to perform rituals in the hospital, requesting the participation of her parents to suppress them. When moving objects in the room, they would need to carry them over her in a certain way several times to complete the ritual without upsetting her. As her admission progressed, her urges became overwhelming, and she ultimately returned to performing the rituals herself. She paced several times across the hospital, resisting the urge to urinate until she had completed the task. This resulted in episodes of pain and distress attributed to acute urinary retention that resolved with voiding. She also regressed developmentally, showing more interest in cartoons targeted for younger children, and continued to refuse to drink, requiring IVF intermittently.
Psychiatry, psychology, and neurology services were consulted to help guide the patient's evaluation and treatment. She underwent a series of tests to identify a secondary cause of her presentation. This included a CBC [mild microcytic anemia], CMP [normal], Lyme serology [normal], brain magnetic resonance imaging (MRI) [mild prominence of sulci likely secondary to dehydration], repeat brain MRI about 3 weeks from the first [normal], lumbar puncture (LP) with opening pressure [normal], cerebrospinal fluid (CSF) microscopy and chemistry [normal], CSF autoimmune profile [normal], electroencephalogram (EEG) [normal], serum autoimmune encephalopathy panel [positive for anti-GAD 65 at 0.05, resulted day 16], serum N-methyl D-aspartate (NMDA) antibodies [negative], and M. pneumoniae serum antibodies [IgG and IgM positive, resulted day 3] with confirmatory M. pneumoniae IgM indirect immunofluorescence assay (IFA) [positive, resulted day 3].
Amongst the consulting services, there were varying opinions regarding the diagnosis and treatment of the patient. Psychiatry cited case reports and experiences with patients with M. pneumoniae infections associated with OCD that responded to azithromycin. At their recommendation, azithromycin was initiated for a 30-day course. However, this was discontinued on day 13 because she developed diarrhea in the setting of underlying dehydration, in addition to a lack of clinical improvement. At this time, psychotropic medications were not started so as not to confound the possible response to azithromycin.
Psychology attempted a reward system to encourage oral (PO) intake, but she continued to intermittently require IVF due to inadequate intake as a result of interference from her rituals.
On day 9 of hospitalization, psychiatry recommended starting intravenous methylprednisolone (1.5 mg/kg/dose), however, no clinical response was observed after a 5-day course. Lorazepam was initiated as needed for agitation and ritual control at this time.
Due to the lack of response to the above treatments (azithromycin, reward system, steroids), intravenous immunoglobulin (IVIG) was considered, however not initiated due to a national shortage. The ultimate decision to attempt plasmapheresis was made on day 16 of hospitalization when the anti-GAD 65 was found to be positive. After her first session of plasmapheresis, she showed some improvement: she was able to participate in Halloween activities (trick-or-treat), and her rituals were less repetitive with an improvement in her PO intake. She received a total of five rounds of plasmapheresis before her compulsions decreased significantly. Sertraline 10 mg daily was initiated on day 23 of hospitalization. She was ultimately discharged after about one month of inpatient care, and continued to follow up with her outpatient psychologist, psychiatrist, and pediatrician. Her outpatient psychiatrist increased her sertraline dosage to 15 mg and added Vitamin D 1000-2000 units daily. She also completed an outpatient intensive behavioral health program after her discharge. Within a few weeks of her discharge, her compulsions and intrusive thoughts had dissipated completely.