• Sources of exposure
  • Battery manufacturing, metallurgy
  • Drinking water (contaminated by lead plumbing) or contaminated sources
  • Lead-containing paint (common source of exposure in children) from:
    • Antique or imported toys
    • Walls of older homes (houses built before 1978 may still have lead-based paint)
• Pathophysiology: inhibition of aminolevulinate dehydratase and ferrochelatase → heme synthesis disruption → ↑ protoporphyrin and ↑ aminolevulinic acid in RBCs
• Clinical features
  • Nervous system
    • Polyneuropathy, encephalopathy, headache, fatigue, muscle weakness, paresthesias, delirium, seizures
    • Demyelination of peripheral nerves→ peripheral neuropathy → paralysis of muscles supplied by the radial or peroneal nerve (wrist/foot drop)
    • Cognitive impairment, memory loss
  • Kidneys: nephropathy
  • Red blood cells: symptoms of anemia
  • Other:
    • Purple-blue line on the gums (lead line or Burton line)
    • Severe abdominal pain (lead colic)
    • Constipation
• Treatment of lead toxicity
  • Decrease exposure
  • Chelation therapy indications:
    • Oral succimer with/without intravenous or intramuscular CaNa₂EDTA (calcium disodium ethylenediamine tetraacetic acid)
      • Children
    • IM dimercaprol (British antilewisite, BAL) with/without CaNa2EDTA
      • Patients with lead encephalopathy