Tirzepatide injection linked to first documented case of Anterior Cutaneous Nerve Entrapment Syndrome (ACNES)

Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is an underdiagnosed cause of chronic abdominal pain, often mistaken for visceral pathology. It results from entrapment of terminal branches of intercostal nerves in the abdominal wall. Current standard-of-care for type 2 diabetes and obesity increasingly involves glucagon-like peptide-1 receptor agonists (GLP-1RAs) like tirzepatide, administered subcutaneously. While their systemic effects are well-characterized, localized adverse events at injection sites, particularly neuropathic ones, remain less explored, presenting a diagnostic challenge for clinicians.

This is a case report detailing a 44-year-old man who developed focal abdominal pain. The patient initiated tirzepatide injections (subcutaneous administration). The primary endpoint was the onset and resolution of abdominal pain. Clinical examination, including Carnett's sign, was used to confirm the ACNES diagnosis. The intervention involved relocating injection sites away from the abdomen and initiating multimodal pharmacotherapy for pain management.

A 44-year-old man experienced new-onset, focal, neuropathic abdominal pain coinciding with the initiation of tirzepatide subcutaneous injections. The pain was localized and consistent with ACNES, confirmed by clinical examination. The temporal relationship between injection initiation and pain onset, coupled with pain resolution upon injection site modification, strongly suggests a causal link. This represents the first documented case linking ACNES directly to GLP-1RA subcutaneous administration. The patient's pain significantly improved after relocating the injection sites away from the abdomen and implementing multimodal pharmacotherapy. This case highlights a previously unrecognized localized adverse event.