A 24-year-old white male presented with a 2-year history of changes to his nails. He stated that the ... No history of possible arsenic exposure. Family history was negative for skin and nail ...

27 The presence of hyperkeratosis suggests arsenic poisoning. If excessive amounts of arsenic are found in the urine, hair or nails or if thallium is present in the urine, the final diagnosis can ...

In some cases, white marks on nails can indicate heavy metal poisoning by lead or arsenic—both of which remain a problem in ...