Chronic abdominal wall pain. Diagnostic validity and costs.

Chronic abdominal wall pain (CAWP) is common and frequently mistaken for visceral pain. We determined the stability of this diagnosis with Main Outcome Measures of: (a) change of pain intensity after local anesthetic-corticosteroid injection, (b) pain relief after three or more months follow-up, and (c) costs of diagnostic procedures for visceral causes of abdominal pain in patients with confirmed CAWP. Seventy-nine patients fulfilled tentative criteria for CAWP; 72 (91%) experienced > or = 50% pain relief with anesthetic injection and were followed for at least three months (mean = 13.8 months). Abdominal pain in four patients was later diagnosed as caused by visceral disease. CAWP was confirmed in 56 of remaining 68 patients; 12 of 19 patients with recurrent pain were unavailable for re-injection of anesthetic. Thirty patients with confirmed CAWP had had diagnostic procedures to exclude visceral disease costing almost $700 per patient. CAWP is usually easily identified and treated; greater awareness should minimize misdiagnosis.