Background: Chronic abdominal wall pain
(CAWP) is often undiagnosed and results in
significant health care use as well as patient
suffering. There are two main types: abdominal
myofascial pain syndrome (AMPS) and anterior
cutaneous nerve entrapment syndrome
(ACNES). Although the 2 conditions share clinical
similarities, they have subtly distinct unique
features.
Objectives: To highlight the current practice,
elucidate the characteristics of the 2 types of
CAWP, and direct the spotlight on abdominal
myofascial pain.
Study Design: Prospective case series.
Setting: Tertiary pain medicine clinic in a university
hospital.
Methods: As a part of a prospective audit of
management of chronic abdominal pain, patients
completed brief pain inventory-short form
questionnaires at baseline and at 3 months posttrigger
point treatment.
Results: All 3 patients were misdiagnosed with
ACNES. Patient 1 was attending the emergency
department once every 5 days prior to being correctly
diagnosed with AMPS. Following trigger
point treatment, there was a significant reduction
in emergency department attendance. Patient 2,
with a 10-year history of lower abdominal pain that
resulted in severe disability, was able to mobilize
following trigger point treatment. Patient 3, with
a high opioid use (360 mg per day), was able to
discontinue opioids following ultrasound-guided
trigger point injection with depot steroids.
Limitations: Open label case series in a small
cohort.
Conclusions: AMPS is as common as the various
visceral inflammatory diseases. Lack of awareness,
ignoring its existence, and misdiagnosing it
may not benefit patients with chronic abdominal
pain.
Key words: Chronic abdominal wall pain, abdominal
myofascial pain syndrome, anterior cutaneous
nerve entrapment syndrome, viscerosomatic
convergence
Misdiagnosing Abdominal Myofascial Pain Syndrome as Anterior
Cutaneous Nerve Entrapment Syndrome: Are we Failing Patients with
Nonspecific Abdominal Pain?
