Lead lines in young infants with acute lead encephalopathy: a reliable diagnostic test.

Fifteen Omani infants, ranging between 2 and 4 months of age, with acute lead encephalopathy underwent plain skeletal radiology. X-rays in all 15 infants revealed dense metaphyseal bands in long bones. These were best seen around the knee joint. Six infants had evidence of multiple lead lines indicating previous episodes of exposure to lead while four infants also had lead lines in the axial skeleton. We suggest that any young infant presenting with an unexplained encephalopathy should undergo an X-ray of the knee and that the presence of dense metaphyseal bands strongly supports the diagnosis of lead poisoning. A plain X-ray of the knee is a cheap, widely available investigation which can be rapidly obtained.