What’s ACNES (anterior cutaneous nerve entrapment syndrome)?

In up to 30 percent of patients with chronic abdominal pain, the source of pain appears to be the abdominal wall, not the viscera (1).  As the name implies this is a pain syndrome thought to be due to the entrapment of cutaneous branches of an intercostal nerve at the level of the rectus abdominis muscle (1).   A third of patients experience pain for >1 year and about 10% for > 5 years before diagnosis of ACNES is made. In about one-half of cases, ACNES begins spontaneously, with the remainder developing after abdominal surgery or pregnancy, or is associated with “sports”, “job “ or “unusual activity” (2).  Identification of abdominal wall trigger points and their infiltration with lidocaine may relieve the pain instantaneously and can serve as a diagnostic test (1).  Surgical neurectomy may be effective in those with only temporary or partial response to repeated lidocaine injections (1).

1. Boelens OBA, Scheltinga MR, Houterman S, et al. Randomized clinical trial of trigger point infiltration with lidocaine to diagnose anterior cutaneous nerve entrapment syndrome. Br J Surg 2013;100:217-221.

2. Boelens OB, Scheltinga MR, Houterman S, et al. Management of anterior cutaneous nerve entrapment syndrome in a cohort of 139 patients. Management of anterior cutaneous nerve entrapment syndrome in a cohort of 129 patients. Ann Surg 2011;254:1054-1058.

What’s ACNES (anterior cutaneous nerve entrapment syndrome)?