Msk Dermatology · Year 2 · from Msk Dermatology
Case 1: Systemic Lupus Erythematosus with Nephritis
Patient Presentation
Demographics: 28-year-old African American woman
Chief Complaint: "I have a rash on my face, my joints hurt, and my legs are swelling."
History of Present Illness: The patient presents with a 6-week history of progressive symptoms including a facial rash that worsens with sun exposure, painful swelling in her hands and knees, fatigue, and bilateral leg swelling that leaves indentations when pressed. She also reports intermittent fevers, hair loss (finding clumps in her hairbrush), and mouth sores that are mostly painless. She noticed her urine has been "foamy" for the past two weeks. She denies any history of similar symptoms.
Past Medical History:
- No significant prior medical history
- Two previous first-trimester miscarriages
Medications:
- Prenatal vitamins (not currently pregnant)
- Ibuprofen occasionally for headaches
Family History:
- Maternal aunt has "lupus"
- Mother has hypothyroidism
Social History:
- Works as a marketing executive
- Non-smoker
- Social alcohol use
Physical Examination
- Vital Signs: BP 152/98 mmHg, HR 92 bpm, Temp 37.8C, BMI 24 kg/m2
- Skin:
- Erythematous malar rash across cheeks and nasal bridge, sparing nasolabial folds
- Diffuse non-scarring alopecia
- Oral: Painless ulcers on hard palate
- Cardiovascular: Distant friction rub heard at left sternal border
- Lungs: Decreased breath sounds at left base
- Extremities:
- Bilateral pitting edema to mid-shins
- Synovitis at bilateral MCPs, PIPs, and wrists (non-erosive pattern)
- Neurologic: Normal
Workup and Results
Laboratory Studies:
| Test | Result | Reference Range |
|---|---|---|
| ANA | 1:640, homogeneous pattern | <1:80 |
| Anti-dsDNA | 320 IU/mL | <30 IU/mL (strongly positive) |
| Anti-Smith | Positive | Negative |
| C3 | 45 mg/dL | 90-180 mg/dL (low) |
| C4 | 8 mg/dL | 16-47 mg/dL (low) |
| ESR | 78 mm/hr | 0-20 mm/hr |
| CRP | 1.2 mg/dL | <0.5 mg/dL |
| Creatinine | 1.4 mg/dL | 0.6-1.2 mg/dL |
| Urinalysis | Protein 3+, RBC 50/hpf, RBC casts | Normal |
| 24-hour urine protein | 3.8 g/day | <150 mg/day |
| Hemoglobin | 9.8 g/dL | 12-16 g/dL |
| WBC | 3,200/mm3 | 4,500-11,000/mm3 |
| Platelets | 98,000/mm3 | 150,000-400,000/mm3 |
| Direct Coombs | Positive | Negative |
| Antiphospholipid antibodies | Anticardiolipin IgG positive | Negative |
Imaging:
- Chest X-ray: Small left pleural effusion, cardiomegaly
- Echocardiogram: Small pericardial effusion, normal EF
Renal Biopsy:
- Class IV diffuse proliferative lupus nephritis
- Active lesions with cellular crescents
- Activity index 12/24, Chronicity index 2/12
Clinical Image
Clinical photograph demonstrating the characteristic malar (butterfly) rash of systemic lupus erythematosus, with erythema over the cheeks and nasal bridge sparing the nasolabial folds. Source: Wikimedia Commons, Public Domain.
Diagnosis
Systemic Lupus Erythematosus with Class IV Lupus Nephritis
2019 EULAR/ACR Criteria (Score >=10 required):
- Malar rash: 6 points
- Oral ulcers: 2 points
- Arthritis: 6 points
- Serositis (pericarditis, pleuritis): 5 points
- Renal (Class IV nephritis with proteinuria): 10 points
- Leukopenia: 3 points
- Thrombocytopenia: 4 points
- Hemolytic anemia (positive Coombs): 4 points
- Anti-dsDNA (high titer): 6 points
- Anti-Smith: 6 points
- Low complement: 3 points
- Total: >10 points - criteria met
Treatment Plan
Induction Therapy for Class IV Lupus Nephritis:
- Mycophenolate mofetil: 1g PO BID, titrate to 1.5g BID
- Methylprednisolone: 1g IV daily x 3 days (pulse), then prednisone 1 mg/kg/day with taper
- Hydroxychloroquine: 200 mg PO BID (all lupus patients unless contraindicated)
Supportive Care:
- ACE inhibitor: Lisinopril 10 mg daily (renal protection, blood pressure)
- Sun protection: SPF 30+ daily, sun avoidance
- Bone protection: Calcium and vitamin D supplementation
- Aspirin: 81 mg daily (given positive antiphospholipid antibodies)
Monitoring:
- Urinalysis and creatinine every 2-4 weeks initially
- Anti-dsDNA and complement levels to track activity
- Complete blood counts monthly
Patient Education:
- Pregnancy should be avoided during active nephritis and on mycophenolate (teratogenic)
- Contraception counseling
- Sun exposure worsens disease
Teaching Points
- SLE demographics: Predominantly affects women of childbearing age; African Americans, Hispanics, and Asians have higher incidence and often more severe disease
- Anti-dsDNA and complement: Rising anti-dsDNA and falling complement often herald disease flares, particularly nephritis
- Lupus nephritis classification: Class IV (diffuse proliferative) is the most severe and requires aggressive immunosuppression; biopsy guides therapy
- Hydroxychloroquine: Foundation of SLE therapy; reduces flares, improves survival, and provides cardiovascular protection
- CRP in lupus: Paradoxically, CRP is often normal or minimally elevated in SLE flares unless serositis or infection is present (ESR is typically elevated)