Introduction

Lead poisoning results in defective ferrochelatase and ALA dehydratase function.

Epidemiology

  • Incidence: 0.10 cases per 100,000 person-years
  • Peak incidence: 40-50 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

Features

Investigations

Investigations
  • the blood lead level is usually used for diagnosis. Levels greater than 10 mcg/dl are considered significant
  • full blood count: microcytic anaemia. Blood film shows red cell abnormalities including basophilic stippling and clover-leaf morphology
  • raised serum and urine levels of delta aminolaevulinic acid may be seen making it sometimes difficult to differentiate from acute intermittent porphyria
  • urinary coproporphyrin is also increased (urinary porphobilinogen and uroporphyrin levels are normal to slightly increased)
  • in children, lead can accumulate in the metaphysis of the bones although x-rays are not part of the standard work-up

Management

Management - various chelating agents are currently used:
  • dimercaptosuccinic acid (DMSA)
  • D-penicillamine
  • EDTA
  • dimercaprol