Case Presentation: Two brothers aged 12 and 16 were referred to the ED from clinic for acute worsening of symptoms in the setting of known mercury exposure. In the preceding six months, both had experienced waxing and waning of non-specific symptoms, including musculoskeletal pain and paresthesias, urinary urgency, non-bloody diarrhea, body aches, night sweats, generalized weakness, weight loss, and truncal rash. In addition, their mother reported progressive declines in their academic performance, as well as personality changes, excessive somnolence, and involuntary movements during sleep. Both brothers had undergone extensive outpatient workup for infectious, rheumatological, and oncologic etiologies that were unrevealing until urine studies revealed elevated mercury levels. On repeat interview, the older brother reported that he had been given a vial of an unknown metallic liquid several months prior to the onset of symptoms. The liquid had frequently leaked and was believed to have aerosolized in their bedroom following recent deep cleaning.Examination of the younger brother was notable for hypothermia (95°F), decreased attentiveness, generalized hyporeflexia, tenderness to palpation of the lower extremities, maculopapular truncal rash (Image 1), and desquamating palmar rash (Image 2). The older brother presented only with cutaneous findings, but given concern for delayed vital sign instability, both were admitted for chelation and close clinical monitoring. The younger brother initially required ICU-level care for temperature support and underwent a full septic workup before deescalation of care. Both were initiated on N-acetylcysteine and selenium per Poison Control recommendations and received neuropsychiatric evaluations prior to discharge, with close multidisciplinary follow-up.
Discussion: Acute symptoms of mercury toxicity include dysgeusia, difficulty breathing, vomiting, and diarrhea, while chronic exposure may present as neurological dysfunction, weakness, fatigue, anorexia, and gastrointestinal disturbances (1). Cutaneous manifestations, such as the desquamating palmar rash and truncal rash seen in our patients, may also arise with mercury inhalation, ingestion, or contact (2). Specific neurological findings include mercurial tremor, characterized by fine muscle fasciculations with coarse periodic shaking, as well as erethism, comprising severe behavior and personality changes, emotional excitability, memory loss, insomnia, depression, fatigue, delirium, and hallucinations (1).For these presenting symptoms, a thorough clinical investigation should also include testing for infectious, autoimmune, and endocrine etiologies. Treatment for acute heavy metal toxicity is chelation with dimercaptosuccinic acid (succimer) (3, 4). However, succimer does not cross the blood-brain barrier and may be less effective in patients presenting with neurological symptoms secondary to chronic toxicity. An alternative regimen of N-acetylcysteine and selenium may confer neuroprotective benefit and improve long-term outcomes (4, 5). Periodic clinical and neuropsychiatric evaluations should accompany monitoring of heavy metal levels to guide dosage and duration of treatment.
Conclusions: Assessment for toxic exposure must be considered in clusters of patients presenting with non-specific systemic symptoms. Treatment depends on severity and chronicity of exposure, and should be coordinated with Poison Control and local public health departments.
