[Pyoderma gangrenosum--an interdisciplinary diagnostic problem].

: Pyoderma gangrenosum is a rare, chronic, progressive and noninfectious necrosis of skin with an unclear etiology. It usually coexists with the systemic disorders. Clinically it appears as a rapidly spreading ulceration in a various location. Pyoderma gangrenosum often starts as pustule, nodule or local inflammation which suggest the diagnosis of bacterial infection of skin such as furuncle or phlegmon so patients with early symptoms could be refered to surgical units. We presented the case of pyoderma gangrenosum which affected a 47-year-old woman. Due to the presumptive diagnosis of phlegmon of the patient's right arm she was initially admitted to surgical ward. Sometimes there are many difficulties with an early diagnosis of pyoderma gangrenosum because of its rarity, distinctness of clinical pictures, lack of characteristic histology and laboratory tests. We would like to emphasize that pyoderma gangrenosum should be always included to the differential diagnosis of a rapidly progressing ulceration of skin especially if there is no response to standard therapy.