Concurrent onset of an eosinophilic ulcer of the oral mucosa with peripheral eosinophilia in a human T-cell leukemia virus type I carrier

We present a case of a 46-year-old Japanese woman with an eosinophilic ulcer of the oral mucosa (EUOM), located in the buccal mucosa, who was found by various examinations to be a human T-cell leukemia virus type I (HTLV-1) carrier with peripheral eosinophilia. Her peripheral eosinophilia and EUOM promptly improved in response to oral corticosteroid therapy. EUOM has been described to be possibly associated with trauma, but its etiology has not been fully elucidated to date. In the present case, the presence of peripheral eosinophilia in addition to the EUOM indicated possible influence of certain immune system abnormalities associated with HTLV-1 infection.