Habit-tic deformity, or “washboard nails,” is a type of body-focused repetitive behavior in which an individual, consciously or subconsciously, uses a finger and/or fingernail, typically the second digit, to repeatedly rub the proximal nail fold of an adjacent fingernail, typically the thumb. This habitual  behavior traumatizes the nail matrix and results in characteristic grooves in the affected nail. While some argue that median canaliform nail dystrophy (MCND) is a distinct clinical entity from habit-tic deformity due to the lack of cuticle involvement in the former, it is more likely that the two lie on a spectrum [1, 2]. Habit-tic deformity is classified as a nail tic disorder [2–4].