Along with acute intermittent porphyria, lead poisoning should be considered in questions giving a combination of abdominal pain and neurological signs. Lead poisoning results in defective ferrochelatase and ALA dehydratase function.

PC

• abdominal pain
• peripheral neuropathy (mainly motor)
• fatigue
• constipation
• blue lines on gum margin (only 20% of adult patients, very rare in children)

Investigations

Labs:

• Blood lead level: Levels greater than 10 mcg/dl are considered significant
• FBC: Microcytic anaemia
• Blood film: 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

Imaging:

• in children, lead can accumulate in the metaphysis of the bones although x-rays are not part of the standard work-up

Management