How to manage a patient with Rheumatoid Arthritis (RA) factor positive, presenting with generalized body pain, loose stool, and fever?

Management of RF-Positive RA Patient with Generalized Body Pain, Loose Stool, and Fever

This patient requires immediate evaluation to exclude infection, particularly tuberculosis and gastrointestinal infections, before any immunosuppressive therapy adjustments, given the combination of fever and diarrhea in an RA patient. 1

Immediate Diagnostic Workup

Infection Screening (Priority)

• Test for tuberculosis (QuantiFERON-TB Gold or PPD) before initiating or adjusting any DMARD therapy, as fever in RA patients on immunosuppression mandates TB exclusion 1
• Stool studies including culture, ova and parasites, Clostridium difficile toxin, and fecal calprotectin to differentiate infectious diarrhea from inflammatory bowel disease 1
• Viral hepatitis screening (HBV, HCV) if not previously done, as these require specific management before DMARD escalation 1
• Blood cultures if fever persists, to exclude bacteremia 1

Rheumatologic Assessment

• Complete joint examination documenting tender and swollen joint counts in all peripheral joints (MCPs, PIPs, wrists, elbows, knees, ankles) and spine 1
• Inflammatory markers: ESR and CRP to assess disease activity 1
• Complete autoimmune panel: ANA, anti-CCP (if not done), RF titer 1
• Plain radiographs of affected joints to evaluate for erosive changes 1

Gastrointestinal Evaluation

• Fecal calprotectin (two measurements 15-20 days apart if elevated) to assess for subclinical IBD, which occurs in approximately 15% of spondyloarthritis patients and can present with diarrhea 1
• Consider colonoscopy if fecal calprotectin persistently elevated or if "red flags" present: nocturnal diarrhea, blood in stool, weight loss, or family history of IBD 1

Management Algorithm Based on Findings

If Infection Identified

• Hold all immunosuppressive DMARDs until infection treated 1
• Treat specific infection appropriately
• Resume RA therapy only after infection resolution and reassessment of disease activity 1

If Active RA Without Infection

For Moderate-High Disease Activity (CDAI >10)

• Initiate or optimize methotrexate 15 mg weekly with folic acid 1 mg daily if DMARD-naive 2, 3
• Baseline monitoring: CBC, liver enzymes, creatinine before starting methotrexate 2, 3
• Contraindications to check: serum creatinine must be normal, no active liver disease (transaminases <450 U), no mucositis 3
• If inadequate response to methotrexate after 3 months, add biologic DMARD (TNF inhibitor, abatacept, or IL-6 inhibitor) 4, 5

For Low Disease Activity or Remission (CDAI ≤10)

• Continue current DMARD regimen without escalation 4
• Monitor every 1-3 months with joint counts and inflammatory markers 2

If IBD-Associated Spondyloarthritis Suspected

Classification criteria: Use ASAS criteria to classify as axial or peripheral SpA 1

Active Peripheral SpA + Active IBD

• First-line: TNF inhibitors (infliximab, adalimumab) at gastroenterological dosing, as these treat both conditions simultaneously 1
• Alternative: IL-12/23 inhibitors (ustekinumab) if TNF inhibitors contraindicated 1
• Avoid: NSAIDs if IBD active, as they may exacerbate intestinal inflammation 1

Active Peripheral SpA + IBD in Remission

• Consider: Standard rheumatologic dosing of biologics, though gastroenterological dosing preferred if history of moderate-severe IBD 1
• Monitor: Disease Activity Index for Psoriatic Arthritis (DAPSA) for peripheral joint activity 1

Critical Pitfalls to Avoid

• Never start immunosuppression without excluding active infection, particularly TB, in a febrile patient with diarrhea 1
• Do not attribute all symptoms to RA flare without investigating gastrointestinal pathology, as 15% of SpA patients have concurrent IBD 1
• Avoid NSAIDs until gastrointestinal pathology excluded, as they increase peptic ulcer risk (especially with corticosteroids) and may worsen IBD 1
• Do not use IL-6 inhibitors if colitis suspected, as they carry risk of intestinal perforation 1
• Screen for comorbidities (diabetes, cardiovascular disease) before corticosteroid use, as these require tight monitoring 1

Monitoring Strategy

• Reassess in 4-6 weeks after treatment initiation with repeat joint examination and inflammatory markers 1
• Repeat stool studies if diarrhea persists despite treatment 1
• Annual TB screening if on biologic therapy for >1 year 1
• Liver function tests every 4-8 weeks on methotrexate 3

Integrated Rheumatology-Gastroenterology Approach

Refer to gastroenterology if any major red flag present (one sufficient): nocturnal diarrhea, hematochezia, unintentional weight loss >5%, or family history of IBD 1

Refer to rheumatology if joint swelling (synovitis) present or symptoms persist despite initial management 1

Shared decision-making between patient and physicians regarding treatment choice improves long-term adherence 1