Chronic abdominal wall pain: a frequently overlooked problem. Practical approach to diagnosis and management.

Chronic abdominal wall pain is frequently misdiagnosed as arising from a visceral source, often resulting in inappropriate diagnostic testing, unsatisfactory treatment, and considerable cost. Its prevalence in general medical practice is unknown, although it may account for about 10% of patients with chronic idiopathic abdominal pain seen in gastroenterological practices. The most common cause appears to be entrapment of an anterior cutaneous branch of one or more thoracic intercostal nerves; myofascial pain and radiculopathy are less frequent. Sharply localized pain and superficial tenderness are suggestive of abdominal wall origin. Carnett's test (accentuated localized tenderness with abdominal wall tensing) is a helpful diagnostic sign, especially when incorporated with other findings. Early exclusion of a parietal source should increase diagnostic accuracy when evaluating patients with chronic abdominal pain. Reassurance of patients by the correct diagnosis and avoidance of precipitating causes is often sufficient treatment. However, accurately placed anesthetic/corticosteroid injections give substantial pain relief to more than 75% of patients, often for prolonged periods, and may be confirmatory for the source of the complaint. The probability of missing visceral disease is small (probably less than 7%) with strict adherence to diagnostic criteria and diligent observation of patients.