Previous reports, as well as the investigations reported here, clearly indicate that desquamative gingivitis is a clinical manifestation of several diseases. Correct identification of the underlying etiology is very important since approximately one-third of the patients with desquamative gingivitis may have cicatricial pemphigoid or pemphigus. These two diseases have broad and sometimes systemic medical implications. In cicatricial pemphigoid, not only the oral mucosa but also the conjunctiva may be involved with subsequent blindness. Because of this, patients with cicatricial pemphigoid should also be examined by an ophthalmologist and may require care of a dermatologist for systemic treatment. In pemphigus, 50% of the cases start with only oral lesions with later development of skin lesions. Because of the life-threatening nature of this disease, patients are usually placed on high systemic doses of corticosteroids. Patients with pemphigus should be referred to a dermatologist immediately.