Use of hair analysis in the diagnosis of heavy metal poisoning: report of three cases.

We report three paediatric cases of suspected heavy metal poisoning that presented with non-specific symptoms. Hair samples of the three patients were sent overseas for analysis; results showed abnormal levels of many elements, including some heavy metals. A diagnosis of heavy metal poisoning was made and chelation therapy was offered to each patient. Blood levels for some heavy metals were subsequently checked and all were within the normal range. The original diagnosis of heavy metal poisoning was therefore not substantiated. The patients did not have a history of exposure to heavy metals or specific clinical features of heavy metal poisoning. The non-invasive nature of hair analysis is tempting, but the validity of such testing in diagnosing heavy metal poisoning is questionable.