What is the best approach to manage a patient with rheumatoid arthritis (RA), psoriasis, and gastritis?

Management of RA, Psoriasis, and Gastritis Triad

This complex triad requires TNF inhibitor therapy as the cornerstone treatment, with methotrexate as the anchor DMARD, while implementing aggressive gastric protection strategies and coordinating care between rheumatology, dermatology, and gastroenterology.

Multidisciplinary Care Framework

Integrated specialist management is essential for this triad. Rheumatologists should primarily manage the RA and coordinate with dermatologists for psoriasis and gastroenterologists for gastritis 1. The 2024 EULAR recommendations emphasize that patients with multiple inflammatory conditions require collaborative care to optimize outcomes across all disease manifestations 1.

First-Line Treatment Strategy

Initiate Methotrexate with Gastric Protection

• Start methotrexate 15-25 mg weekly immediately as the anchor DMARD for both RA and psoriasis 1, 2
• Methotrexate is specifically preferred when clinically relevant psoriasis coexists with inflammatory arthritis 1
• Critical caveat: Monitor transaminases carefully in psoriatic arthritis patients, as hepatotoxicity risk is higher than in RA alone 1

Gastritis Management Considerations

• NSAIDs should be avoided or used with extreme caution given the gastritis, despite their role as first-line therapy for musculoskeletal symptoms in psoriatic arthritis 1
• If NSAIDs are necessary, use the lowest effective dose with proton pump inhibitor (PPI) co-therapy 1
• Consider local corticosteroid injections for symptomatic joints as adjunctive therapy to minimize systemic NSAID exposure 1

Bridge Therapy

• Add prednisone 10-15 mg daily as short-term bridge therapy for rapid symptom control while awaiting DMARD effect 1, 2
• Taper glucocorticoids as rapidly as clinically feasible to minimize gastric irritation 1

Escalation to Biologic Therapy

TNF Inhibitor Selection

If inadequate response to methotrexate by 3 months, escalate to a TNF inhibitor combined with methotrexate 1. TNF inhibitors are the preferred first-line biologic for this triad because they:

• Effectively treat both RA and psoriasis 1
• Can be safely combined with methotrexate 3
• Have established efficacy across multiple inflammatory domains 1

Specific TNF inhibitor options include adalimumab, infliximab, etanercept, certolizumab, or golimumab 1, 3. Adalimumab 40 mg subcutaneously every other week is FDA-approved for both RA and psoriatic arthritis 3.

Critical Safety Monitoring with TNF Inhibitors

Screen for tuberculosis and hepatitis before initiating TNF inhibitor therapy 1. The gastritis component requires additional vigilance:

• Monitor for gastrointestinal perforation risk, particularly if there is underlying diverticular disease or inflammatory bowel disease 3
• Continue PPI therapy throughout TNF inhibitor treatment given the gastritis history
• Avoid combining TNF inhibitors with other biologic DMARDs due to increased infection risk without added benefit 3

Concomitant Methotrexate Reduces Immunogenicity

Continue methotrexate when adding a TNF inhibitor to reduce anti-drug antibody formation and maintain efficacy 3. In RA patients receiving concomitant methotrexate, the incidence of anti-adalimumab antibodies was only 1% compared to 12% with monotherapy 3.

Alternative Biologic Pathways

If TNF Inhibitor Fails or Is Contraindicated

Switch to IL-17 inhibitor or IL-12/23 inhibitor if TNF inhibitor therapy fails or is contraindicated 1. The 2019 ACR/NPF guidelines conditionally recommend:

• Switching to IL-17 inhibitor over IL-12/23 inhibitor for active disease 1
• IL-17 or IL-23 inhibitors are particularly effective for severe psoriasis 1

Important consideration: IL-17 inhibitors may theoretically worsen inflammatory bowel disease, though gastritis alone is not a contraindication 1. If there is any concern for underlying IBD (given the gastritis), TNF inhibitors remain the safer choice 1.

Treatment Targets and Monitoring

Treat-to-Target Strategy

Aim for clinical remission or low disease activity using validated composite measures 1:

• For RA: SDAI ≤3.3 (remission) or ≤11 (low disease activity) 2, 4
• For psoriatic arthritis: Absence of clinical and laboratory evidence of significant inflammatory disease activity 1
• Reassess disease activity every 1-3 months and adjust therapy if target not achieved by 6 months 1, 2

Monitoring Parameters

• Joint examination for synovitis, dactylitis, and enthesitis at each visit 1, 4
• Acute phase reactants (CRP preferred over ESR) 2, 4
• Liver function tests (especially important with methotrexate in psoriatic patients) 1
• Complete blood count and comprehensive metabolic panel 4
• Skin assessment for psoriasis severity 1

Common Pitfalls to Avoid

1. Do not delay DMARD therapy while attempting NSAID monotherapy, given the gastritis and need for aggressive disease control 1, 2

2. Do not use NSAIDs without adequate gastric protection in patients with known gastritis 1

3. Do not combine multiple biologic agents due to increased infection risk without added benefit 3

4. Do not overlook cardiovascular risk assessment, as both RA and psoriasis are associated with increased cardiovascular disease 5, 6

5. Do not ignore extra-articular manifestations including uveitis, which may require additional specialist involvement 1

6. Do not use live vaccines while on TNF inhibitor therapy 3

Special Considerations for This Triad

Gastrointestinal Surveillance

Maintain heightened awareness for inflammatory bowel disease development, as psoriasis and psoriatic arthritis are associated with IBD 7, 6, 8. Red flags requiring gastroenterology referral include:

• Rectal bleeding, chronic abdominal pain, perianal fistula/abscess, chronic diarrhea, or nocturnal symptoms 8
• These symptoms warrant prompt gastroenterology evaluation even if already on treatment 8

Dosing Considerations

Use gastroenterology-appropriate dosing if there is concern for underlying IBD, even if the IBD is currently inactive 1. For example, if TNF inhibitor therapy is needed and there is suspicion of IBD, consider higher dosing regimens approved for Crohn's disease or ulcerative colitis 3.

Hepatotoxicity Monitoring

Monitor liver function more frequently than in RA alone, given the increased hepatotoxicity risk of methotrexate in psoriatic arthritis, especially with alcohol consumption, obesity, or diabetes 1.