You are describing onycholysis, which is when the nail separates from the underlying bed. In this scenario, air under the lifted nail appears as a white or yellow discoloration. You will observe the normal white tip of the nail begin to track toward the cuticle. This may occur for a number of reasons. New onset onycholysis can indicate that something is going on with the thyroid. Your client should be referred to her dermatologist or primary care physician for laboratory testing. Another scenario and the more likely cause is that your client may have developed an allergy to one of the chemicals in the acrylic causing the nails to separate. Even if the client has been wearing acrylics for years an allergy can still develop. The other possibility is that the nails are being cleaned with an implement too vigorously. This can cause separation of the nail from the underlying bed. Regardless of the scenario, your client should be seen by a dermatologist so that she can be treated in a prompt manner. Onycholysis is relatively easy to treat if caught early, but if it persists it can cause permanent separation of the nail from the underlying nail bed.
— Dana Stern, M.D. is a board-certified dermatologist specializing in nails. She works in private practice in New York City.