Rectus sheath hematoma caused by non-contact strenuous exercise mimicking acute appendicitis

A healthy 26-year-old man visited the Emergency Department due to right lower quadrant pain of 2 days' duration that developed after wakeboarding. There was no history of direct trauma to the abdomen. Physical examination revealed tenderness and rebound tenderness on the right lower quadrant area. There was no palpable abdominal mass. Computed tomography (CT) of the abdomen was undertaken to discern the causes of acute abdomen, including acute appendicitis. CT revealed a small-size rectus sheath hematoma beneath the lower end of the right rectus muscle. The patient was admitted for supportive care including pain control and was discharged with improvement after 5 days. Rectus sheath hematoma can be caused by not only a direct blow but also non-contact strenuous exercise, for example, wakeboarding in this case. Although the majority of rectus sheath hematomas are self-limiting, some can cause peritoneal irritation signs, mimicking acute abdomen, and eventually lead to unnecessary laparotomy without clinical suspicion and ancillary tests including CT scan and ultrasonography.