60-Year-Old Woman with Known SLE - Off Treatment 6 Years - Presenting with Polyarthritis

Clinical Problem Summary

Step 1: Differential Diagnosis

Most Likely: SLE Arthritis Flare

• SLE arthritis is typically a symmetric polyarthritis involving the wrists, MCPs, and PIPs - exactly the pattern described here.
• EMS is a classic feature of inflammatory arthritis.
• Being off treatment for 6 years significantly increases flare risk.
• Key feature: SLE arthritis is classically non-erosive and non-deforming, though in some patients periarticular ligament damage may lead to Jaccoud-like deformity (reducible subluxations, distinct from RA).
• Harrison's (2025): "Lupus arthritis is characterized by a polyarthritis most commonly involving the wrists, the MCP and PIP joints of the hands, and the knees."

Important Differential: Rhupus (SLE + RA Overlap)

• RA and SLE can occur simultaneously - this overlap is termed "Rhupus".
• Features that would favor Rhupus over pure SLE arthritis: erosive changes on X-ray/MRI, RF/anti-CCP positivity, more deforming arthritis, nodules.
• Emerging MRI/ultrasound studies suggest SLE can occasionally show erosive changes, but less severe than RA.

Other Differentials to Exclude

Step 2: Key History to Take

• Duration and pattern of joint involvement (additive vs. migratory)
• Any other SLE features currently: rash, photosensitivity, oral ulcers, hair loss, chest pain/breathlessness (serositis), hematuria, frothy urine (nephritis), neurological symptoms
• Why treatment was stopped 6 years ago (side effects? remission? non-compliance?)
• Prior medications (especially steroids - raises AVN risk)
• Family history of RA
• Signs of infection (fever, recent illness)
• Menstrual/hormonal history (menopause - post-menopausal women can flare)

Step 3: Investigations

Immediate / Baseline

Serological (Disease Activity Markers)

To Differentiate from RA / Rhupus

Additional

• Blood cultures (if fever present, to exclude septic arthritis/infection)
• Parvovirus B19 IgM/IgG (if viral illness history)
• Calculate SLEDAI score to quantify disease activity

Clinical tip: In SLE flares, CRP is characteristically normal or only mildly elevated despite significant synovitis. A markedly elevated CRP should raise suspicion for concurrent infection or serositis, rather than SLE activity alone.

Step 4: Management

Overall Goal

A. Restart Disease-Modifying Therapy

• Dose: up to 5 mg/kg/day (actual body weight)
• Indicated for arthritis, skin, fatigue, serositis, and to prevent flares
• Benefits: reduces flare frequency, improves survival, reduces thrombosis risk (especially if antiphospholipid antibodies present), safe in pregnancy
• Monitoring: Baseline retinal exam, then annual ophthalmology review (retinal toxicity risk with prolonged high-dose use)
• Side effects: GI symptoms (nausea, diarrhea), rash, skin dyspigmentation, rare cardiomyopathy

B. For Active Joint Inflammation (Short-Term)

• NSAIDs (e.g., naproxen, celecoxib): for mild joint pain/stiffness while HCQ takes effect (4-8 weeks onset), but caution with renal function and CV risk
• Low-dose glucocorticoids (e.g., prednisone 5-15 mg/day): if more severe arthritis or if NSAIDs insufficient; taper to ≤5 mg/day as quickly as possible

C. If Inadequate Response to HCQ (Moderate Disease)

• Methotrexate (MTX): particularly useful for arthritis-dominant lupus (also used in Rhupus)
• Azathioprine (AZA): good steroid-sparing agent
• Mycophenolate mofetil (MMF): especially if renal involvement
• Belimumab (BEL): biologic (anti-BLyS), approved for active SLE, reduces flares
• Anifrolumab (ANI): anti-IFN-alpha receptor biologic, newer option for moderate-severe non-renal SLE

D. General Measures (ALL patients)

• Daily sunscreen on sun-exposed areas
• Regular exercise, healthy diet, normal BMI
• No smoking
• Blood pressure, lipid, glucose monitoring and control
• Vaccination compliance (avoid live vaccines if on immunosuppressives)
• Osteoporosis prophylaxis if on long-term steroids (calcium + vitamin D, consider bisphosphonate)

SLE Arthritis vs. RA - Key Distinguishing Features

Treatment Algorithm (EULAR 2023, Harrison's 2025)

• Harrison's Principles of Internal Medicine 22E (2025), Chapter 368
• Goldman-Cecil Medicine, Hydroxychloroquine section

Bottom Line for This Patient

1. This presentation is most consistent with a SLE flare with polyarthritis after 6 years off treatment.
2. Rule out Rhupus (send RF, anti-CCP, hand X-rays), concurrent RA, and infection.
3. Assess for other organ involvement - especially lupus nephritis (urine PR:CR, renal function) and cytopenias.
4. Send disease activity markers: anti-dsDNA, C3/C4, CBC.
5. Restart HCQ immediately (first-line, all SLE patients) + short-course low-dose glucocorticoids/NSAIDs for acute relief.
6. Calculate SLEDAI score and set target of remission or low disease activity.
7. Educate on importance of not stopping treatment once started.