[Case of acute pharyngitis caused by Corynebacterium ulcerans in Ibaraki Prefecture].

We report on the case of a 51-year-old woman who presented with refractory pharyngitis caused by toxigenic Corynebacteriumn ulcerans (C. ulcerans). Thick pseudomembrane formations and yellowish pus were observed in her nasopharynx. Based on her clinical course and history of breeding cats, we considered C. ulcerans infection as the possible diagnosis. She was treated with macrolide administration and her symptoms immediately improved. C. ulcerans was identified in pus from the patient's pharynx as well as in discharge material from her cat's eyes, and C. ulcerans was thought to have caused her pharyngitis. C. ulcerans is one of the infecting bacteria which can cause a zoonotic infection. In Japan, some cases with C. ulcerans infection from cats have been reported. It is important that we should consider C. ulcerans infection as a differential diagnosis of refractory pharyngitis.