[Accidental mercury poisoning in a 12-year-old girl]

Exposure to metallic mercury can cause severe accidental intoxications in children, whose clinical symptoms can vary depending on the route of administration, the dose, as well as the time and duration of the exposure. It has become unusual in France, yet it must be considered when taking a patient's medical history in cases of multisystemic involvement without a clear explanation.

We report the case of a 12-year-old patient hospitalized because of a cough, poor general condition, chills, night sweats, psychomotor retardation, and skin lesions that had been developing for several weeks. The initial clinical examination also revealed sinus tachycardia, arterial hypertension, and abolition of osteotendinous reflexes. Complementary examination results were normal apart from a glomerular proteinuria without renal failure. When interviewing the mother, she reported that the child had played with mercury balls 3 months earlier. The suspicion of poisoning was confirmed by blood and urine analysis as well as renal biopsy showing an aspect of membranous glomerulonephritis with IgG and C3 depositions. An intoxication via a transdermal route being unlikely on healthy skin, the Regional Health Agency's survey concluded that chronic intoxication had occurred by inhalation of the mercury spread on the floor at the time of the exposure, which was then vacuum cleaned and released again by the contaminated vacuum cleaner. The patient's outcome was favorable within a few weeks after initiating DMSA chelation therapy.

Mercury poisoning should be considered in cases of a multisystemic disorder without clear explanation, in order to intervene quickly and thus prevent irreversible renal and neurological consequences.