She greeted the patient cheerfully, then took a long look at his nails. They weren't purple, but dark gray or black. And the coloring wasn't even. It looked kind of grainy. The cuticle was not affected, nor was the nail fold directly behind it.
A common cause of discolored nails is medication. Years ago gold was used to treat rheumatoid arthritis. It can cause bluish pigmentation on the skin and sometimes the nails. Had he ever been treated with gold? Never, he said flatly. What about silver? This is sometimes added to supplements that people buy off the internet. He never used any nutritional supplements. There are other drugs that can do this – the most common are antibiotics, especially members of the tetracycline family – but the patient was not taking any of them. Heavy metals like arsenic, lead or mercury can also cause nail discoloration. But the man looked far too healthy to be exposed to toxin levels sufficient to produce these findings.
A closer look
The doctor noticed that only the fingers were involved; The nails on the thumbs were normal. To the dermatologist, this and its grainy appearance suggested the discoloration was coming from the outside rather than the inside. She picked up her dermatoscope – a kind of souped-up magnifying glass with a powerful built-in light to assess pigmented lesions on the skin. Upon closer inspection of the nail, she could see that the area of color was actually created by hundreds of tiny black grains on the outside of the nail and not inside the nail itself. She asked him about his hobbies. Did he paint or work with his hands? No Pickleball only. She had seen people with this type of discoloration on their fingers while reading the newspaper, but never on their nails.
Suddenly she asked: "Does your wife dye her hair?" She did it, said the man. "Do you ever help her?" Never. She would never let him, he said with a smile. It didn't look like the man had dyed his hair – it was gray. She was silent for a minute. "I used a new shampoo," the man offered. He was in the drug store and saw a shampoo that said it could get rid of the gray and restore the hair's natural color. His son got married in the fall and he thought it would be nice if he got his old hair color back. "But it's not a dye," he insisted. Also, he added, it didn't work.
Show me how you shampoo your hair, asked Burnett. The man began massaging his scalp, using all four fingers on each hand but no thumb. Burnett was certain of her diagnosis and took a small package from a drawer. When she tore it open, the man recognized the smell of acetone: nail polish remover. The dermatologist rubbed a nail briskly and almost immediately the gray discoloration broke off and the nail stayed close to its original color.
The product he uses "Just for Men Control GX Gray Reduction Shampoo" does not use the word "dye" in its advertising or packaging. The company's promotional material states that the product “mimics the universal pigment found in a strand of hair to create each person's natural hair color. With each use, the gray hair is gradually re-pigmented. “The material suggests that this is a natural process that they have tapped into. In fact, it's a dye hidden in a shampoo.