What is the approach to skin evaluation and management in an adolescent patient with systemic lupus erythematosus (SLE) presenting with skin symptoms?

Skin Evaluation in Lupus

In an adolescent with SLE presenting with skin symptoms, perform a skin biopsy for histological confirmation, classify the cutaneous lesions into acute, subacute, or chronic subtypes, and obtain comprehensive autoantibody testing (ANA, anti-dsDNA, anti-Ro/SSA, anti-La/SSB, anti-RNP, anti-Sm) along with complement levels (C3, C4) to assess for systemic involvement. 1

Initial Clinical Assessment

Characterize the Cutaneous Lesions

• Document the specific morphology and distribution of skin lesions to classify them into one of three major subtypes 1:

  • Acute cutaneous LE (ACLE): Malar "butterfly" rash or generalized photosensitive eruption, most strongly associated with systemic disease 2, 3
  • Subacute cutaneous LE (SCLE): Annular or papulosquamous plaques on sun-exposed areas (upper back, shoulders, neck, chest), highly photosensitive and frequently associated with anti-Ro/SSA antibodies 1, 2
  • Chronic cutaneous LE (CCLE): Discoid lesions with indurated scaly plaques causing scarring, hyperpigmentation, and alopecia, typically on scalp, face, and ears 2, 3

• Use the Cutaneous Lupus Disease Area and Severity Index (CLASI) to quantify disease activity and damage at baseline and follow-up 1

• Assess for non-specific manifestations including non-scarring alopecia (present in 86.67% of SLE patients), oral ulcers, vasculitic lesions, Raynaud's phenomenon, and periungual changes 4, 5

Mandatory Skin Biopsy

• Obtain skin biopsy from an active lesion for histological analysis to confirm the diagnosis of cutaneous lupus 1
• Repeat biopsy if clinical morphology changes or treatment fails 1

Essential Laboratory Workup

Baseline Autoantibody and Complement Testing

• Order comprehensive autoantibody panel: ANA, anti-dsDNA, anti-Ro/SSA, anti-La/SSB, anti-RNP, anti-Sm, anti-phospholipid antibodies 1
• Measure complement levels: C3 and C4, as low complement combined with positive anti-dsDNA strongly supports active SLE 6
• Pay special attention to anti-Ro/SSA and anti-La/SSB in adolescent females, as these antibodies are frequently associated with SCLE and carry risk for neonatal lupus and congenital heart block in future pregnancies 1, 2

Additional Baseline Tests

• Complete blood count to assess for cytopenias 1, 6
• Serum creatinine and albumin to screen for renal involvement 1, 6
• Urinalysis with urine protein/creatinine ratio to detect lupus nephritis 1, 6
• Erythrocyte sedimentation rate and C-reactive protein 1, 6

Excluding Systemic Lupus Erythematosus

Screen for Major Organ Involvement

• For abnormal urinalysis or elevated creatinine: Obtain urine protein/creatinine ratio, perform urine microscopy, order renal ultrasound, and consider referral for kidney biopsy 1
• Monitor for neuropsychiatric symptoms: Seizures, paresthesias, numbness, weakness, headache, depression, and cognitive impairment 1
• Assess for serositis, arthritis, and hematologic abnormalities 4, 6

Apply Classification Criteria

• Use EULAR/ACR 2019 criteria as the standard for SLE classification, requiring positive ANA (≥1:160) plus clinical and immunologic criteria 6
• Remember that ACLE has the strongest association with systemic disease, SCLE intermediate, and discoid LE the least 3

Management Approach

First-Line Interventions

• Photoprotection is mandatory for all patients due to high photosensitivity: SPF 60+ sunscreen containing zinc oxide or titanium dioxide, sun avoidance, and protective clothing 4, 1, 3
• Strongly counsel on smoking cessation, as smoking impairs response to antimalarial therapy 4, 7
• Topical corticosteroids for localized lesions 7

Systemic Therapy

• Antimalarials (hydroxychloroquine) are first-line systemic therapy for cutaneous lupus not controlled with topical measures 4, 2, 7
• For refractory cases, consider azathioprine as third-line treatment 1
• In patients requiring chronic glucocorticoids who cannot taper to acceptable doses, add immunosuppressive agents such as azathioprine, mycophenolate mofetil, or methotrexate 4

Ongoing Monitoring

Regular Follow-Up Testing

• Monitor every 6-12 months with CBC, ESR, CRP, serum albumin, creatinine, urinalysis, anti-dsDNA, C3, and C4 levels 1, 6
• Repeat anti-dsDNA and complement levels at follow-up visits even if previously negative/normal, as some patients develop these markers during flares 8
• At each visit, assess disease activity using validated indices (SLEDAI, BILAG, or SLE-DAS), skin damage, quality of life, comorbidities, and medication adverse events 1, 8

Critical Pitfalls to Avoid

• Do not rely solely on ANA testing for diagnosis, as it can be positive in other conditions 1
• Screen for drug-induced SCLE, as multiple medications can trigger this subtype 1, 2
• In adolescent females, re-evaluate anti-Ro/SSA and anti-La/SSB antibodies before any future pregnancy due to risk of neonatal lupus and congenital heart block 1
• Avoid mycophenolate mofetil, cyclophosphamide, and methotrexate in pregnancy 4, 1
• Maintain high index of suspicion for co-morbidities including infections, atherosclerosis, hypertension, dyslipidemia, and osteoporosis 4