Which organ systems are typically affected in lead poisoning?

• A. GI, respiratory, and dermatologic
• B. GI, neuro, and hematopoietic
• C. Cardiovascular signs only
• D. Renal signs only

Answer: (B)

Lead poisoning typically involves several organ systems, with the most characteristic impact on the gastrointestinal tract, the nervous system, and the hematopoietic system.

Gastrointestinal effects arise from smooth muscle irritation and colicky abdominal pain, often with constipation and anorexia. In exposed individuals, this can be a prominent complaint.

Nervous system involvement is especially important: adults often develop peripheral neuropathy such as wrist or foot drop, while children may exhibit cognitive and behavioral changes or developmental delays. Neurologic toxicity can be the most serious consequence of exposure in kids.

Hematopoietic effects come from lead’s inhibition of key enzymes in heme synthesis, notably δ-aminolevulinic acid dehydratase and ferrochelatase. This disruption leads to microcytic, hypochromic anemia and can produce characteristic basophilic stippling on a blood smear.

Lead also can cause renal proximal tubule dysfunction with chronic exposure, but the combination of gastrointestinal, neurological, and hematopoietic findings best represents the typical organ systems affected.

That’s why this pattern—GI symptoms, neuro effects, and hematologic changes—best fits lead poisoning.