In a patient with psoriasis presenting with epigastric pain radiating to the back, what is the most likely diagnosis and how should it be evaluated and managed?

Epigastric Pain Radiating to the Back in a Patient with Psoriasis

The most likely diagnosis is acute pancreatitis, and you should immediately evaluate with serum lipase or amylase (≥3× upper limit of normal) and obtain CT abdomen with contrast or abdominal ultrasound to confirm the diagnosis and assess for complications. 1

Most Likely Diagnosis: Acute Pancreatitis

Epigastric pain radiating to the back is the classic presentation of acute pancreatitis, requiring only two of three diagnostic criteria: (1) characteristic epigastric pain radiating posteriorly, (2) lipase/amylase ≥3× upper limit of normal, or (3) confirmatory imaging findings. 2, 3

Critical Medication Review in Psoriasis Patients

You must immediately review this patient's medication list because several psoriasis treatments can trigger acute pancreatitis:

• Systemic corticosteroids – These are contraindicated in psoriasis and can cause severe disease deterioration, but if the patient received them anyway, withdrawal can precipitate pancreatitis. 1, 4, 5

• Furosemide and other diuretics – Commonly prescribed and frequently overlooked as a cause of drug-induced pancreatitis. 3

• Methotrexate – A first-line systemic agent for extensive psoriasis that can cause pancreatitis, particularly in elderly or infirm patients. 1, 4

• Cyclosporin – Used at 3-5 mg/kg/day for moderate-to-severe psoriasis and is a known cause of pancreatitis. 4

• Biologic agents (TNF inhibitors like infliximab, adalimumab, etanercept) – These are increasingly used for severe psoriasis and psoriatic arthritis but carry pancreatitis risk. 1, 4, 5

Immediate Diagnostic Workup

Order these tests immediately:

• Serum lipase or amylase – Elevation ≥3× upper limit of normal confirms pancreatitis. 2

• Fasting lipid panel with triglycerides – Hypertriglyceridemia >1,000 mg/dL causes pancreatitis; levels >2,000 mg/dL represent very severe hypertriglyceridemia requiring aggressive management. 2

• CT abdomen with IV contrast (preferred) or abdominal ultrasound – To identify pancreatic necrosis, fluid collections, and rule out gallstones. 1

• Complete metabolic panel – To assess for organ dysfunction and guide fluid resuscitation. 6

• Complete blood count – Leukocytosis indicates severity; activated leukocytes infiltrating the pancreas drive systemic inflammation. 6

Alternative Diagnoses to Consider

While pancreatitis is most likely, the ACR Appropriateness Criteria explicitly state that epigastric pain radiating to the back should prompt evaluation for:

• Acute aortic syndromes – Obtain CT angiography if vascular risk factors present or hemodynamic instability. 1

• Myocardial infarction – Check troponin and ECG, especially if exertional dyspnea or cardiac risk factors exist. 1

• Penetrating posterior peptic ulcer – Less likely with back radiation but consider if NSAID use (common in psoriatic arthritis). 1

Management of Confirmed Acute Pancreatitis

If pancreatitis is confirmed, initiate supportive care immediately:

• Aggressive IV fluid resuscitation – Lactated Ringer's at 250-500 mL/hour initially to prevent organ failure. 2, 6

• Pain control – Adequate analgesia is essential; do not withhold opioids. 6

• NPO status initially – Advance diet as tolerated when pain improves; early feeding (within 24-48 hours) is beneficial in mild cases. 6

• Discontinue the offending medication – If drug-induced pancreatitis is suspected, stop the causative agent permanently. 3

Special Management for Hypertriglyceridemia-Induced Pancreatitis

If triglycerides >1,000 mg/dL:

• Subcutaneous insulin – Activates lipoprotein lipase to rapidly lower triglycerides. 2

• Fibrates and statins – Initiate once oral intake resumes. 2

• Consider plasmapheresis – For triglycerides >2,000 mg/dL or severe pancreatitis, though insulin therapy may suffice. 2

Severity Stratification and Prognosis

Approximately 20% of acute pancreatitis cases progress to severe disease with:

• Local complications – Pancreatic necrosis, abscess, or pseudocysts requiring intervention. 6

• Systemic organ failure – Respiratory, renal, or cardiovascular dysfunction requiring ICU care. 6

• Systemic inflammatory response syndrome (SIRS) – Overwhelming cytokine production leading to early organ failure, followed by compensatory anti-inflammatory response that increases infection risk. 6

Common Pitfalls to Avoid

Do not assume psoriasis is unrelated to the presentation – The medications used to treat psoriasis (methotrexate, cyclosporin, biologics) are direct causes of pancreatitis and must be reviewed. 1, 4, 3

Do not overlook drug-induced pancreatitis – A careful medication history is essential; furosemide and other common drugs are frequently missed causes. 3

Do not delay imaging – While lipase confirms pancreatitis, CT imaging is necessary to identify complications (necrosis, fluid collections) that alter management and prognosis. 1, 6

Do not restart systemic corticosteroids – Even if the patient's psoriasis flares during pancreatitis treatment, systemic steroids are absolutely contraindicated and can cause fatal psoriasis deterioration. 1, 4, 5