Frequency and severity of systemic disease in patients with subacute cutaneous lupus erythematosus.

OBJECTIVE: To compare the frequency and severity of systemic disease in patients with subacute cutaneous lupus erythematosus (SCLE) followed up in a dermatology practice vs patients with systemic lupus erythematosus (SLE) followed up in a rheumatology practice.

DESIGN: Case-control comparison of patients matched for age, sex, and ethnicity.

SETTING: University-affiliated dermatology and rheumatology practices.

PATIENTS: Seventy-six patients with SCLE were compared with 24 patients with SLE.

INTERVENTION: All medical records were reviewed and the patients were interviewed.

MAIN OUTCOME MEASURES: Systemic and serologic findings were compared between patients with SCLE and those with SLE.

RESULTS: Hematologic disorders were present in 6 patients (8%) with SCLE and in 13 patients (54%) with SLE (P<.001). Serositis was present in 1 patient (1%) with SCLE and in 3 patients (12%) with SLE (P =.04). Renal involvement was present in 12 patients (16%) with SCLE and in 6 patients (25%) with SLE (P =.36). Antinuclear antibodies were found in 52 patients (68%) with SCLE compared with 23 patients (96%) with SLE (P =.006). Anti-Ro antibodies were found in 37 patients (49%) with SCLE compared with 10 patients (42%) with SLE (P =.64). Other serologic abnormalities (anti-native DNA, anti-Sm antibody, or anti-U(1)RNP) were present in 6 patients (8%) with SCLE compared with 15 patients (62%) with SLE (P<.001). Photosensitivity was present in 65 patients (86%) with SCLE, compared with 11 patients (46%) with SLE (P<.001).

CONCLUSIONS: This analysis reveals a dissimilar frequency of internal organ involvement between patients with SCLE and SLE. Renal disease was similar in frequency and severity, and documented central nervous system involvement was rare in both groups.