Abdominal Cutaneous Nerve Entrapment Syndrome: The Cause of Localized Abdominal Pain in a Young Pregnant Woman

A 26 years old primigravida woman presented with abdominal cutaneous entrapment syndrome: a case report

BACKGROUND

Abdominal cutaneous nerve entrapment syndrome (ACNES) is characterized by severe, mostly refractory, chronic pain due to the entrapment of the cutaneous branches of the lower torso intercostal nerves at the lateral edge of the rectus abdominis muscle. ACNES is rare compared to other pregnancy-related peripheral neuropathies and is often overlooked as a differential diagnosis for abdominal pain, despite the diagnosis relying primarily on patient history and physical examination. Emergency physicians and other medical personnel's lack of exposure to such cases results in unnecessary laboratory requests, repeated visits, and increased fear and tension for the patient.

CASE PRESENTATION

A 26-year-old primigravida on her second trimester of pregnancy presented to our Emergency department with persistent localized right upper quadrant abdominal pain. Despite repeated visit to the nearby hospital, no diagnosis was settled and the pain persisted. At our ED after a thorough history, physical examination and diagnostic test no abnormality was found. Finally Abdominal cutaneous nerve entrapment syndrome (ACNES) was considered and a mixture of 1 ml 2% lidocaine with adrenaline and 1 ml dexamethasone (4 mg) was infiltrated into the fascial plane in a fanning fashion into the most tender area using a modified technique and the patient reported significant improvement in pain.

CONCLUSION

Abdominal cutaneous nerve entrapment syndrome (ACNES) is a cause of abdominal pain in pregnancy that is often overlooked. The objective of this study is to describe a rare case of ACNES in a 26-year-old primigravida woman who presented to a low-resource emergency department to assist patient management.

Diagnostic Effect of Consultation Referral from Gastroenterologists to Generalists in Patients with Undiagnosed Chronic Abdominal Pain: A Retrospective Study

This study aimed to investigate consultation outcomes from gastroenterologists to generalist physicians for the diagnostic workup of undiagnosed chronic abdominal pain. This was a single-center, retrospective, descriptive study. Patients were included who were ≥15 years old and consulted from the Department of Gastroenterology to the Department of Diagnostic Medicine, to establish a diagnosis for chronic abdominal pain, at the Dokkyo University Hospital from 1 April 2016 to 31 August 2020. We retrospectively reviewed the patients' medical charts and extracted data. A total of 12 cases were included. Eight patients (66.7%) were diagnosed with and treated for functional gastrointestinal disorders (FGID) at the Department of Gastroenterology; their lack of improvement under treatment for FGID was the reason for their referral to the Department of Diagnostic Medicine for further examination. After this consultation, new possible diagnoses were generated for eight patients (66.7%). Six of the eight patients (75.0%) were diagnosed with abdominal wall pain (anterior cutaneous nerve entrapment syndrome, n = 3; myofascial pain, n = 1; falciform pain, n = 1; and herpes zoster non-herpeticus; n = 1). Consultation referral from gastroenterologists to generalists could generate new possible diagnoses in approximately 70% of patients with undiagnosed chronic abdominal pain.

Recurrent anterior cutaneous nerve entrapment syndrome (ACNES) in three consecutive pregnancies

A 31-year-old G2P1001 woman at a 30-week gestation presented with a recurrence of pinpoint right upper abdominal wall pain. She had been diagnosed with an anterior cutaneous nerve entrapment syndrome (ACNES) during her first pregnancy at a similar gestational age, a well-described but frequently under-recognised entity. The pain during that pregnancy resolved immediately and completely following normal spontaneous vaginal delivery, however,the pain was worse with this presenting pregnancy. She underwent an ultrasound-guided rectus sheath nerve block at 30 weeks with complete and immediate relief for the remainder of the pregnancy. During a third pregnancy, she suffered another recurrence; however, it was less severe than in the prior pregnancies and was managed conservatively. It again resolved completely and immediately with normal spontaneous vaginal delivery. The pattern of ACNES recurrence during the same gestational age in all three pregnancies with total relief following deliveries demonstrates a clear primary mechanical aetiology.