White nails are referred to as leukonychia and the causes are potentially vast. Your description implies discrete white patches and the most common possibilities include punctuate leukonychia or keratin granulations. Punctuate leukonychia are white spots that are secondary to trauma to the nail matrix. Aggressive manicuring, or damage to the cuticle perhaps when your client’s acrylics were removed, can damage the nail matrix and consequently white patches appear. With time they can grow out; however, sometimes trauma can result in permanent and irreversible damage to the matrix with resultant permanent nail alteration. We see punctuate leukonychia in children’s nails a lot because children are trauma prone. Alternatively, keratin granulations are superficial white patches that appear when nail polish is removed along with the superficial keratin layers of the nail. A nail polish holiday is an easy remedy in this case.
— Dana Stern, M.D. (www.drdanastern.com) is a board-certified dermatologist specializing in nails. She works in private practice in New York City.
Editor’s note: We recommend you refer you client to a doctor to get a definitive diagnosis