What can we do in regard to therapy for patients with an abdominal wall source of pain?
Many patients with abdominal wall pain have anterior cutaneous nerve entrapment syndrome (ACNES). Patient’s with this often have discrete areas of tenderness on exam, often on the lateral edge of the rectus sheath, frequently on the right side of the abdomen. Anesthetic injection at the point of tenderness provides immediate relief for patients with ACNES, and is helpful in confirming the diagnosis.
Boelens and colleagues did injections in 48 patients suspected of having ACNE, randomizing half to receive lidocaine and half to receive saline placebo.5The majority of the patients receiving lidocaine (54%) had a response, compared with 17% of placebo patients (P less than .007).
Greenbaum and colleagues studied 79 patients with chronic abdominal wall pain.6 In this study, 72 of 79 patients had greater than 50% pain relief with anesthetic injection and were followed for a mean of almost 14 months. Only four of these patients ended up having a visceral cause of pain.
Can using injections help pain from ACNES longer term?
Koop and colleagues looked at all published studies in regards to both immediate and longer-term pain relief with injections.7 Both lidocaine injections and injections with lidocaine plus steroids led to long-term pain relief (40%-50% of patients with multiple lidocaine injections and up to 80% with lidocaine plus steroid injections). I think that injections are certainly worth a try in patients with chronic abdominal wall pain.
Pearl
Consider chronic abdominal wall pain in your differential diagnoses for patients with chronic abdominal pain, and use Carnett sign to help with diagnosis.
Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at imnews@mdedge.com.
References
1. Costanza CD et al. Clin Gastroenterol Hepatol. 2004 May;2(5):395-9.
2. Thomson WH et al. Br J Surg. 1991 Feb;78(2):223-5.
3. Thomson H, Francis DM. Lancet. 1977 Nov 19;2(8047):1053-4.
4. Gray DW et al. Ann R Coll Surg Engl. 1988 Jul;70(4):233-4.
5. Boelens OB et al. Br J Surg. 2013 Jan;100(2):217-21.
6. Greenbaum DS et al. Dig Dis Sci. 1994 Sep;39(9):1935-41.
7. Koop H et al. Dtsch Arztebl Int. 2016 Jan 29;113(4):51-7.