Hypertension artérielle par intoxication au mercure: intérêt diagnostique du captopril

Abstract

background. - Mercury poisoning is a rare cause of hypertension in children. Urinary excretion sometimes remains low despite severe clinical intoxication. Case report. - A 23 month-old girl was admitted with hypertension, tachycardia, apathy, irritability and excessive sweating. Erythromelalgia and neurologic symptoms permitted the diagnosis of acrodynia. Urine mercury remained normal until chelation. Captopril significantly increased urine mercury concentration but failed to improve clinical manifestations. Clinical improvement required infusions of BAL® for 5 days then oral dimer-captosuccinic acid for 3 months. Metal vapors originated from the mercury which spilled from a broken thermometer onto the carpet. Comments. - Low basal urine mercury could be associated with real mercury poisoning. Small amounts of metal mercury held in a thermometer could produce a high level of mercury vapor leading to intoxication in young children. The binding capacity of metal ions by captopril could be used to increase urine mercury output. Nevertheless, captopril therapy fails to improve acrodynia. Total elimination of mercury requires long-term therapy with BAL® or dimercaptosuccinic acid. Conclusions. - An unexpected mode of intoxication and low basal urine mercury are not decisive arguments against mercury poisoning, which is the only cause of acrodynia.