[Intradermal metal deposits in an industrial worker]

We describe a 75-year-old patient with asymptomatic grey pigmentation on the face and fingers. He had worked over two decades in cutting high-voltage cables. The cutting procedures were performed without a face shield or protection gloves. The patient presented with gray punctate lesions beside some homogeneously stained zones.

Histologically, the deposits presented in the dermal tissue in a horse-shoe, oval, or splinter-like shape. The foreign body material was embedded by a few CD68-positive macrophages. Undyed histological sections were investigated via two-dimensional micro-synchrotron X-ray fluorescence analysis (SRXRF). The deposits were identified as zinc (Zn), copper (Cu), nickel (Ni), and strontium (Sr), which were strongly associated with maximal sulfur (S) concentrations. This association is presumably induced by complex binding between thiol groups and metal ions such as Zn, Ni etc. However, the iron (Fe) distribution patterns were quite different to those of Zn, Cu, or Ni. These heavy metals are major components of the metal wires that the patient worked with in his profession.

To the best of our knowledge, this is the first case report in the dermatological literature of intradermal metal deposits identified via SRXRF analysis.