[Hallucinations during treatment with hydrochloroquine]. / Hallucinations au cours d'un traitement par hydroxychloroquine.

INTRODUCTION: We report an unexpected cenesthetic hallucination-type neuropsychiatric side effect with hydrochloroquine (Plaquenil) in a patient treated for an erosive plantar lichen planus. OBSERVATION: A 75 year-old woman was hospitalized for a handicapping erosive plantar lichen. Treatment with hydrochloroquine (400 mg/day) was initiated, associated with topical corticosteroids and a short course of oral acorticosteroids (0.5 mg/kg/day of methylprednisolone). After 10 days of treatment, a short episode of temporo-spatial disorientation occurred, followed by a feeling of depersonalization and cenesthetic hallucinations with feelings in the body. These manifestations were preceded by nightmares. Hydrochloroquine was spontaneously stopped by the patient one week later and led to the progressive disappearance of the hallucinations and a return to a normal mental state within one month. Two and a half years later, no relapse of the psychiatric manifestations has been noted. DISCUSSION: Chloroquine and hydrochloroquine may be at the origin of severe psychosis-like psychiatric side effects. Such manifestations are exceptional, little known and principally described during treatment of malaria. The clinical presentation of the psychosis induced by synthetic ani-malarials is fairly homogeneous from one case to the next: onset in a patient without psychiatric past of manifestations such as delirium, hallucinations, maniac episodes or depression after an interval of a few hours to 40 days, usually regressing one week after suspension of the synthetic antimalarial. There is no relationship between the dose of synthetic anti-malarial administered and the onset of psychiatric problems. The triggering-off mechanism is unknown and appears to be an idiosyncratic reaction. Our case report draws the dermatologists' attention to the possibility of the occurrence of potentially severe psychiatric side effects.