[The rectus abdominis syndrome]

Three athletes (one female, two males), aged 18-21 years, developed acute abdominal pain, two of them immediately after exercise including abdominal muscle training. The female patient had a pulmonary infection of uncertain cause at the time. The second patient obviously suffered from an allergic or parasitic disease (eosinophilia of 26%). The third patient, a swimmer, had the symptoms in the course of a flu-like infection after drinking about 100 g alcohol. Serum creatinine kinase activity was 7,800-17,500 U/l, making acute muscle damage likely, probably rhabdomyolysis. Ultrasound examination revealed echo-dense areas of the rectus abdominis muscle in two of the patients, in one of them associated with marked muscle swelling. In the third patient ultrasound was unremarkable during a symptom-free interval 8 days after the onset of symptoms. These observations indicate that even during banal infections sport exercise involving special strain on the abdominal musculature should not be undertaken because of the risk of rhabdomyolysis.