Involvement of mucosal surfaces is also uncommon. Lesions are usually less than 1-2 cm in size. There is no known malignant potential. Although WD is microscopically similar to Darier disease, WD is thought to be unrelated to the systemic disorder. There is no known racial predilection.
Patients report insidious onset or slight recent enlargement of the lesion.
Lesions with a similar appearance can rarely be found involving mucosal surfaces. Rarely, subungual presentation has been documented. One extraordinary case presented as a longitudinal red ridge within the nail plate. Chemical carcinogens have been theorized to be causative, although no data exist to support this conclusion. Ultrastructural findings have been interpreted to suggest that acantholysis is due to a defect in desmosome-tonofilament complexes.