Necrotizing fasciitis caused by a primary appendicocutaneous fistula

We report a case of necrotizing fasciitis in the loin of a 76-year old man with several coexisting or past health issues, including diabetes mellitus, hypertension, alcohol-related liver cirrhosis, gastrectomy for gastric cancer, subarachnoid hemorrhage, normal pressure hydrocephalus, and cerebral infarction. Incision of the necrotizing fasciitis was successful, but it revealed an appendicocutaneous fistula; thus, we performed appendectomy and fistulectomy. We think that the necrotizing fasciitis was caused by appendicitis perforation involving the retroperitoneum, inducing the formation of an appendicocutaneous fistula. Necrotizing fasciitis and appendicocutaneous fistulae are rare complications of appendicitis. Moreover, to our knowledge, this is the first report of fluoroscopic examination demonstrating that a primary appendicocutaneous fistula had caused necrotizing fasciitis. Our search of the literature found 12 cases of necrotizing fasciitis caused by preoperative appendicitis. We discuss the characteristics and findings of these cases.