A 70-year-old man was referred to our hospital with the chief complaint of painful and intractable erosions of the oral mucosa. We performed radiation therapy for tongue cancer in March 2000. Then, in February 2001, neck dissection was performed for left cervical lymphadenopathy. No recurrence of the tumor was noted thereafter. In June 2011, the patient visited a nearby hospital with some bleeding sores in the mouth. As no improvement was noted with the usual treatment, oral bacterial pharyngitis was suspected and the patient was referred to our hospital. After admission, we performed biopsy suspecting recurrence of squamous cell carcinoma, however, no evidence of cancer recurrence was detected. Thereafter, skin biopsy and the test for anti-desmoglein antibody confirmed the diagnosis of pemphigus vulgaris. Patients with pemphigus vulgaris can present with mucosal lesions as the only initial symptom. For refractory oral, pharyngeal and laryngeal lesions, it is important to bear in mind the possibility of pemphigus vulgaris in the differential diagnosis. The test for anti-desmoglein antibody is highly specific, and useful as a minimally invasive test for the diagnosis and treatment of pemphigus vulgaris. Our present case exemplifies the usefulness of this test.
