What is the most appropriate management for a 20‑30‑year‑old patient with celiac disease presenting with diarrhea, weight loss, arthralgia, positive tissue transglutaminase antibodies, and markedly elevated rheumatoid factor (~600 U/mL)?

Management of Celiac Disease with Arthralgia and Elevated Rheumatoid Factor

Initiate a strict, lifelong gluten-free diet immediately—this is the definitive treatment for celiac disease and will resolve both the gastrointestinal symptoms and the arthralgia in this patient. 1, 2

Primary Management: Gluten-Free Diet

The cornerstone of treatment for this patient is complete gluten avoidance (wheat, rye, and barley). The positive tissue transglutaminase antibodies confirm active celiac disease, and the arthralgia is an extraintestinal manifestation that will resolve with dietary treatment 3. In a directly comparable case of a 28-year-old with polyarthritis and elevated anti-transglutaminase antibodies (200 U/mL), joint symptoms completely resolved within 3 weeks of starting a gluten-free diet 3.

Key Points About the Elevated Rheumatoid Factor

• The elevated RF (~600 U/mL) is likely a false positive or non-specific finding in the context of active celiac disease
• Celiac disease causes immune dysregulation that can produce elevated autoantibodies, including RF, without indicating true rheumatoid arthritis
• Do not treat for rheumatoid arthritis at this time—the arthralgia is an extraintestinal manifestation of celiac disease 3, 4
• The absence of erosive arthropathy on examination and the young age with acute presentation favor celiac-related arthralgia over RA

Immediate Clinical Actions

Nutritional Assessment and Supplementation

Given the diarrhea and weight loss, assess for:

• Iron deficiency anemia (most common)
• Vitamin D deficiency
• Vitamin B12 and folate deficiency
• Calcium levels
• Albumin (marker of protein malnutrition)

Supplement deficiencies as identified 1.

Dietitian Referral

Refer to a dietitian experienced in celiac disease for comprehensive education on:

• Reading food labels for hidden gluten
• Cross-contamination avoidance
• Nutritionally balanced gluten-free eating
• Common pitfalls in gluten-free diet adherence 1

Monitoring Strategy

Short-term Follow-up (3-6 months)

• Clinical response: Expect resolution of diarrhea, weight gain, and improvement in arthralgia within weeks to months 3
• Repeat tissue transglutaminase antibodies: Should decline significantly with dietary adherence 1
• Reassess nutritional parameters: Recheck deficiencies identified initially

Reassess the Rheumatoid Factor

• Recheck RF after 6-12 months on gluten-free diet—it may normalize as celiac disease comes under control
• If arthralgia persists despite documented dietary adherence and normalized celiac serology, only then consider formal rheumatology evaluation
• If RF remains elevated but patient is asymptomatic, no treatment is needed

Critical Pitfall to Avoid

Do not start immunosuppressive therapy (steroids, DMARDs) for presumed rheumatoid arthritis in this patient. The arthralgia is almost certainly celiac-related given the acute presentation with classic GI symptoms and positive celiac serology 3. Starting unnecessary immunosuppression would expose the patient to significant risks without benefit.

When to Consider Alternative Diagnoses

If symptoms do not improve after 3-6 months of strict gluten-free diet:

• Verify dietary adherence (most common cause of non-response)
• Rule out inadvertent gluten contamination
• Consider small bowel bacterial overgrowth
• Reassess for refractory celiac disease (rare in newly diagnosed patients)
• Only then pursue formal rheumatology workup if arthralgia persists 1, 5

Prognosis

With strict gluten-free diet adherence, expect:

• Diarrhea resolution: Within days to weeks
• Weight gain: Progressive over months
• Arthralgia improvement: Within 3 weeks based on similar cases 3
• Antibody normalization: Gradual decline over 6-12 months 1

The elevated RF should not distract from the primary diagnosis and treatment of celiac disease, which will address all of this patient's presenting symptoms.