Application of Point-of-Care Ultrasound Scanning for the Diagnosis of Perianal Abscess.

A sixty-year-old man with ulcerative colitis and polymyalgia rheumatica, for which he was receiving prednisolone, visited the emergency department complaining of a gradual worsening of pain in the right buttock. Physical examination revealed mild redness and tenderness at the right side of the anus. Ultrasound revealed an approximately 38-mm long, avascular subcutaneous collection with heterogeneous echogenicity in the tender region. A perianal abscess was diagnosed, the lesion was punctured, and pus was drained, after which the pain improved. Point-of-care ultrasonography was effective in the prompt diagnosis and subsequent treatment of this patient's perianal abscess.