[Hallucinations: Etiological analysis of children admitted to a pediatric emergency department]

Children's hallucinations pose the dual challenge of diagnosing a possible medical emergency and a possible psychiatric disorder.

The main objective was to analyze the causes of such hallucinations in children presenting to a pediatric emergency department.

We conducted a single-center, observational, retrospective study including all children aged less than 15 years experiencing hallucinations and admitted to our tertiary level pediatric emergency department between 1 January 2007 and 31 December 2015. The data collected were demographic; medical: previous medical or psychiatric history, current medications, associated clinical or psychiatric symptoms, type and character of hallucinations, length and recurrence of hallucinatory phenomena; and other biological, radiological and neurological explorations.

Sixty-eight patients were included (29 boys). The mean age was 9.1±3 years (range, 2-14 years and 10 months; median, 9.2 years). Admissions were seasonal with a bimodal distribution (a peak during springtime and another one during fall). Hallucinations were mainly visual (90%), acute (77%) and complex (63%). Visual hallucinations were associated with other types of hallucinations: auditory (n=17), somatosensory (n=7). Fifteen children had a psychiatric history and had already experienced hallucinatory phenomena (93%). Among 47 patients (69%), these hallucinations were associated with other symptoms: agitation (41%), headaches (28%), hyperthermia (21%) and negative symptoms of the schizophrenia spectrum (15%). On admission, 20 patients (29%) had one or more treatments under way (34 drugs, 41% known for hallucinogenic adverse effects). Neurological explorations were undertaken in half of the cases. Toxicological analysis prescribed in 19 children was positive in five cases (26%). Fifty-three percent of patients were hospitalized and 51 children received a specialized follow-up (by a neurologist and/or a psychiatrist). A nonpsychiatric origin of these hallucinations was diagnosed in 29 patients (43%): neurological causes (n=10), infectious diseases (n=10), intoxications (n=5) and a medication side effect (n=4).

Hallucinations with a suspected underlying psychiatric cause differed on several factors: chronic duration (p=0.02), an onset after 10 years of age (p=0.004), previous identical episodes (p=0.014) and a parental psychiatric history (p=0.036), auditory hallucinations (p=0.0009), absence of fever (p=0.005), headaches (p=0.036) and the presence of negative symptoms of the schizophrenic spectrum (p=0.02).