• Sources of exposure
  • Organometallic methylmercury in fish
• Clinical features
  • Acute toxicity
    • Gastroenteritis (bloody diarrhea)
    • Kidney failure
    • Inflammation of the airways (from inhalation exposure)
  • Chronic toxicity (Minamata disease)
    • Cardiovascular/sympathetic nervous system: Mercury inactivates catechol O-methyltransferase, an enzyme responsible for catecholamine breakdown. Therefore, mercury toxicity leads to increased serum and urinary epinephrine and norepinephrine, causing excess stimulation of the sympathetic nervous system (similar to pheochromocytoma). Symptoms include diaphoresis, tachycardia, hypertension, and anxiety.
    • Neuropsychiatric: Mercury can cross the blood-brain barrier and deposit in the CNS, specifically the cerebral cortex, leading to a range of psychiatric and motor symptoms (eg, personality changes, insomnia, tremor); photophobia may also be seen.
    • Dermatologic: Mercury toxicity, particularly in children, can lead to a hypersensitivity rash (acrodynia). A diffuse, pruritic body rash or a desquamating, pink rash on the palms and soles is characteristic.