Abdominal Wall Pain: Clinical Evaluation, Differential Diagnosis, and Treatment.

Abdominal wall pain is often mistaken for intra-abdominal visceral pain, resulting in expensive and unnecessary laboratory tests, imaging studies, consultations, and invasive procedures. Those evaluations generally are nondiagnostic, and lingering pain can become frustrating to the patient and clinician. Common causes of abdominal wall pain include nerve entrapment, hernia, and surgical or procedural complications. Anterior cutaneous nerve entrapment syndrome is the most common and frequently missed type of abdominal wall pain. This condition typically presents with acute or chronic localized pain at the lateral edge of the rectus abdominis that worsens with position changes or increased abdominal muscle tension. Abdominal wall pain should be suspected in patients with no symptoms or signs of visceral etiology and a localized small tender spot. A positive Carnett test, in which tenderness stays the same or worsens when the patient tenses the abdominal muscles, suggests abdominal wall pain. A local anesthetic injection can confirm the diagnosis when there is 50% postprocedural pain improvement. Point-of-care ultrasonography may help rule out other abdominal wall pathologies and guide injections. The management of abdominal wall pain depends on the etiology. Reassurance and patient education can be helpful. Local injection with an anesthetic and a corticosteroid is an effective treatment for anterior cutaneous nerve entrapment syndrome, with an overall response rate of 70% to 99%. For refractory cases that require more than two injections, surgical neurectomy generally resolves the pain.