Contact exposure to elemental iron causing chromonychia.

An orange-brown chromonychia developed on the toenails of a woman after a geographic move resulted in exposure to rural well water. Samples of the water and qualitative and quantitative examination of nail clippings confirmed the fact that the source for the discoloration was contact exposure to elemental iron. Installation of water purification equipment resulted in resolution of the nail stain over a six-week period of time.