Anaemia and unexplained abdominal pain: looking for a lead

The anaemia of lead poisoning is caused not only by impaired haem synthesis but also by inhibition of intracellular iron delivery to ferrochelatase; this results in increased incorporation of zinc into protoporphyrin, which explains the high concentrations of zinc protoporphyrin. 8 Although it is not sensible to screen all cases of unexplained anaemia for lead intoxication, 9 the presence of other relevant symptoms such as abdominal pain should raise suspicion. Strict regulation of industry and the removal of lead from petrol, food cans, and paint have greatly reduced lead exposure. 12 Even though occupational exposure has steadily decreased over time, the number of cases with a non-occupational cause has remained relatively steady and is reported to range between 11% and 75% of cases with blood lead levels of 600 [mu]g/L or greater. 13 Heavy metal contamination has been identified in many commercially available herbal supplements and remedies. 14 In a survey of 6712 women, those using herbal supplements had lead levels 10% higher than non-users; women using ayuverdic remedies had blood lead levels 24% higher than non-users. 15 About 80% of India's population use ayuverdic remedies. 16 With recent increases in travel, migration, and the availability of these products in health food stores and over the internet, heavy metal poisoning as a result of ingestion of contaminated products also occurs in the Western world. A reduction in the blood lead level after initial chelation is often followed by a rebound increase owing to redistribution from storage areas such as the skeleton. 18 Patient outcome Our patient improved symptomatically and his anaemia resolved within two months of discontinuing the ayuverdic remedies. Because his blood lead level was very high, and after we sought advice from the National Poisons Information Service, he received DMSA at a dose of 30 mg/kg for five days.