Definition: Stylonychia is a disease characterized by the presence of small, white patches on the skin that can be painful and often cause discomfort or even pain in certain areas. These patches may appear anywhere on the body, but they are most commonly found on the face, neck, hands, and feet. The exact causes of this condition are not fully understood, but it is thought to be related to an autoimmune response to a particular virus that has been identified as responsible for causing the disease.