Argyria associated with colloidal silver supplementation.

A 65-year-old male presented for skin examination and was incidentally noted to have discoloration of the fingernails. These findings were completely asymptomatic. The patient had been taking colloidal silver supplementation (Silverzone 140 ppm silver Gifts of Nature, St. George, UT, USA) for 2 years as therapy for diabetes. He first noticed the onset of nail discoloration 1 year ago. His past medical history included type II diabetes and hypertension. His current medications were metformin, glyburide, and benazepril. Physical examination revealed slate-gray discoloration involving the lunulae of the fingernails (Fig. 1). The skin, mucous membranes, and sclerae were unaffected.