Superficial Abdominal Wall Pain (Musculoskeletal Origin)
This patient's superficial right-sided abdominal pain that responds to topical diclofenac gel is most likely musculoskeletal in origin—specifically abdominal wall pain from muscle strain, nerve entrapment, or soft tissue inflammation—and is unrelated to the grade 2 fatty liver disease.
Clinical Reasoning
The key diagnostic features pointing away from visceral pathology include:
- Superficial location with pain localized to the skin and subcutaneous tissues rather than deep visceral structures 1
- Dramatic response to topical NSAIDs, which would not effectively penetrate to treat intra-abdominal pathology 2
- Absence of systemic symptoms (no fever, no peritoneal signs, no hemodynamic instability) that would suggest serious intra-abdominal disease 1
- No alarm features such as nocturnal awakening, progressive worsening, or associated gastrointestinal symptoms 1
The grade 2 fatty liver is an incidental finding in this context. Fatty liver disease does not cause superficial abdominal wall pain 3. NAFLD-related pain, when present, would be deep visceral discomfort in the right upper quadrant, not superficial and responsive to topical therapy 3.
Diagnostic Approach
Perform a focused physical examination looking for:
- Carnett's sign: Increased pain with tensing of abdominal wall muscles (patient lifts head/shoulders while supine) indicates abdominal wall rather than visceral origin 1
- Point tenderness over a specific location that reproduces the patient's pain
- Absence of peritoneal signs (no rigidity, no rebound tenderness, no guarding) 1
- Normal vital signs (no tachycardia, no hypotension, no fever) 1
Imaging is not indicated unless red flags emerge. The ACR Appropriateness Criteria for right upper quadrant pain prioritize ultrasound only when biliary or hepatic pathology is suspected 3. This patient's superficial pain with topical NSAID response does not warrant imaging 3, 1.
Management Plan
Continue topical diclofenac gel to the affected area 2-4 times daily as needed. Topical NSAIDs provide effective analgesia for musculoskeletal pain with minimal systemic absorption 2, 4.
Reassure the patient that this pain is unrelated to the fatty liver disease and represents a benign musculoskeletal condition 1.
Address the fatty liver separately with appropriate lifestyle modifications:
- Target 7-10% body weight loss through gradual reduction (<1 kg/week) 3, 5
- Mediterranean diet emphasizing vegetables, fruits, whole grains, and olive oil 3, 5
- Vigorous-intensity exercise ≥150 minutes weekly 5
Monitor for resolution within 2-4 weeks. If pain persists or worsens despite topical therapy, consider alternative diagnoses including nerve entrapment syndromes 1.
Critical Pitfalls to Avoid
Do not attribute superficial abdominal wall pain to fatty liver disease. NAFLD does not cause this type of pain presentation 3.
Do not order unnecessary imaging (ultrasound or CT) for clearly musculoskeletal pain without red flags, as this leads to incidental findings, increased costs, and patient anxiety 3, 1.
Avoid systemic NSAIDs in this patient with fatty liver disease. While diclofenac hepatotoxicity is rare (occurring in <1% of users), it can cause serious liver injury particularly with chronic use 6, 7, 8. Topical formulations provide adequate analgesia with negligible hepatic exposure 2.
Do not pursue rapid weight loss for the fatty liver, as weight loss >1 kg/week can precipitate acute hepatic failure in patients with underlying liver disease 5, 9.
When to Escalate
Seek further evaluation if: