Annular lesions of subacute cutaneous lupus erythematosus. Erythematous plaques with a trailing scale and slight central clearing are present on this patient's arm.
Papulosquamous lesions of subacute cutaneous lupus erythematosus. Scaly, erythematous plaques are present on this patient's leg. These lesions simulated lichen planus.
Manifestations of systemic disease in patients with subacute cutaneous lupus erythematosus (SCLE) and systemic lupus erythematosus (SLE). ANA indicates antinuclear antibody; asterisk, P<.05.
Black DR, Hornung CA, Schneider PD, Callen JP. Frequency and Severity of Systemic Disease in Patients With Subacute Cutaneous Lupus Erythematosus. Arch Dermatol. 2002;138(9):1175-1178. doi:10.1001/archderm.138.9.1175
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.
Case-control comparison of patients matched for age, sex, and ethnicity.
University-affiliated dermatology and rheumatology practices.
Seventy-six patients with SCLE were compared with 24 patients with SLE.
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.
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-U1RNP) 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).
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.
SUBACUTE CUTANEOUS lupus erythematosus (SCLE) is a distinct form of lupus erythematosus (LE) that is characterized by nonscarring, non–atrophy-producing skin lesions.1 It is associated with anti-Ro/SS-A antibodies. Many patients with SCLE fulfill 4 or more of the American College of Rheumatology (ACR) diagnostic criteria2 for systemic lupus erythematosus (SLE).3,4 Most patients with SCLE are believed to have a chronic or relapsing but benign process, with few of the serious manifestations of SLE, such as central nervous system or renal disease.5 However, reports of severe systemic disease occurring in patients with SCLE suggest that the full spectrum of LE-associated disease is possible.4,6 We are aware of only 1 case-control study7 of patients with SCLE and SLE, which revealed similar frequency and severity of systemic disease in age- and sex-matched patients. The purpose of the present investigation was to review a larger group of patients with SCLE (follow-up, 2 to >10 years) and to compare them with a cohort of patients (matched for age, sex, and ethnicity) with SLE and without SCLE skin lesions and followed up in a rheumatology practice.
Seventy-six patients with SCLE were included in this study (follow-up, 2 to >10 years), which was conducted by physicians at a university-affiliated private practice: Associates in Dermatology, PLLC, Louisville, Ky. The diagnosis of SCLE was based on characteristic clinical features, combined with histopathologic confirmation of an interface dermatitis, as previously described by Sontheimer et al3 and Callen and Klein.4 The lesions were characterized as annular, papulosquamous, or tumid, based on the major type of involvement present. We included tumid LE within this study because these patients have photosensitive, nonscarring, non–atrophy-producing lesions. Although some would classify such patients as having chronic cutaneous LE because of the chronic nature of the disease, many of our patients with other forms of SCLE also display a chronic or recurrent course. We did not exclude patients with SCLE who fulfilled the ACR diagnostic criteria for SLE.6
Control subjects were selected from patients with SLE who were followed up by physicians at Rheumatology Associates, Louisville. Patients with SLE consenting to participate in our research project were matched by age (±2 years), sex, and ethnicity with at least 1 of our patients with SCLE. Criteria for inclusion as a control subject were informed consent and nonparticipation in dermatologic follow-up for SCLE. We did not exclude patients who had lesions of discoid LE, malar erythema, or photosensitivity. The diagnosis of SLE was based on fulfillment of 4 or more of the ACR criteria.6
Clinical and laboratory data were obtained from reviews of medical records from the practices. Medical records were also obtained from each patient's primary care physician, nephrologist, hematologist, and neurologist, when applicable. The data collected included age, sex, ethnicity, age at onset of disease, medications at onset, type of skin disease, activity of disease, history of photosensitivity (abnormal reaction to light as observed by a physician or as reported by the patient), joint disease (arthralgias or arthritis), Sjögren syndrome (documented by a physician), serositis (pleuritis or pericarditis), results of complete blood count and urinalysis, total hemolytic complement studies, and serologic testing. We defined a hematologic disorder as the presence of hemolytic anemia, leukopenia, or thrombocytopenia, and a renal disorder as hematuria, proteinuria, or renal failure. Each patient was interviewed to discuss his or her case at length. This study was reviewed and approved by the Human Studies Committee of the University of Louisville. Symptom or prevalence rates were compared using χ2 and Fisher exact tests, with α set at .05, 2-sided.
The mean age of the study population was 59.1 years for patients with SCLE and 54.5 years for patients with SLE. The age at onset of SCLE ranged from 19 to 85 years, and for SLE, 30 to 78 years. At the onset of disease, 3 patients with SCLE were taking medications that may have caused or exacerbated their cutaneous disease; however, in all 3 patients the disease continued after the medications were stopped. There were 58 women with SCLE (56 white and 2 African American) and 18 men (all white). There were 22 women with SLE (21 white and 1 African American) and 2 men (both white) (Table 1).
The SCLE lesions were classified as annular (Figure 1), papulosquamous (Figure 2), or tumid. Annular disease occurred in 36 patients, papulosquamous disease in 30, and tumid disease in 3. Six patients had lesions of mixed characteristics. One patient's lesions were unclassified.
Forty-eight of the patients with SCLE fulfilled 4 or more ACR diagnostic criteria for SLE. However, the frequency of systemic disease in patients with SCLE varied from that observed in patients with SLE (Figure 3). Hematologic disorders, including leukopenia, hemolytic anemia, and thrombocytopenia, were present in 13 (54%) of 24 patients with SLE. Only 6 (8%) of 76 patients with SCLE experienced hematologic disorders (P<.001).
Photosensitivity was more common in patients with SCLE (65 SCLE [86%] vs 11 SLE [46%]) (P<.001). Forty-seven patients (62%) with SCLE experienced arthritis vs 100% of the 24 patients with SLE (P<.001). Serositis was present in 3 patients (12%) with SLE vs 1 (1%) with SCLE (P = .04). Renal disease, including hematuria, proteinuria, casts, and renal failure, occurred in 12 patients (16%) with SCLE vs 6 patients (25%) with SLE (P = .36). Antinuclear antibody (ANA) was a common finding in both patient groups (52 [68%] patients with SCLE vs 23 [96%] with SLE) (P = .006). Among the 24 patients with SCLE without ANAs, 17 (71%) were photosensitive, 11 (46%) had arthritis, and 5 (21%) had anti-Ro/SS-A antibodies. Serologic abnormalities other than a positive ANA or anti-Ro/SS-A were more prevalent in patients with SLE (15 [62%] patients with SLE vs 6 [8%] with SCLE) (P<.001). Anti-Ro/SS-A was pressent in 10 patients (42%) with SLE and in 37 patients (49%) with SCLE (P = .64). Thirty-three (51%) of 65 photosensitive patients were anti-Ro/SS-A–positive, while 3 (27%) of 11 nonphotosensitive patients were positive for this antibody. Renal disease was present in 4 (11%) of 37 anti-Ro/SS-A–positive patients. Among our 3 patients with tumid LE, 2 were ANA-positive, 1 was anti-Ro/SS-A–positive, and all 3 were photosensitive. Sjögren syndrome was present in 11 (46%) of 24 patients with SLE vs 33 (43%) of 76 patients with SCLE (including all 3 of the patients with tumid LE).
The clinical and immunologic differences between patients with SCLE with annular vs papulosquamous lesions are presented in Table 2. Patients with annular SCLE had more frequent photosensitivity, more often developed arthritis, and were more frequently positive for ANA and anti-Ro/SS-A).
Subacute cutaneous lupus erythematosus is characterized by nonscarring, non–atrophy-producing skin lesions. These lesions occur predominantly on the face, upper chest, upper back, and arms in a photosensitive distribution. An association with the anti-Ro/SS-A antibody has been established, although the skin abnormalities are requisite for diagnosis. Most of our patients with SCLE had 4 or more of the ACR diagnostic criteria for SLE.
Cohen and Crosby7 performed the first case-control study of systemic disease associated with SCLE. Their data suggested that the patients with SCLE might not be as clinically homogeneous as previously believed. They demonstrated that the frequency and severity of renal and neurologic disease in patients with SCLE were comparable to or greater than those found in patients with SLE who did not have SCLE skin lesions. Despite these findings, dermatologists generally perceive that patients with SCLE have a better prognosis than those with SLE, with less frequent and less severe renal and central nervous system disease.
Chlebus and colleagues8 attempted a comparative study of patients with SCLE vs SLE. They found dissimilar frequency and severity of internal organ involvement, with patients with SCLE being less severely affected. However, their study had 2 biases that are addressed in the present study. First, their cohorts were not age- and sex-matched; the SCLE group was 10 years older and contained fewer women. Second, their definition of the patients with SCLE was not the same as that used by Sontheimer et al1; the presence of photosensitivity was used to define their patients with SCLE. Although photosensitivity is a common manifestation of SCLE, its presence is not the defining characteristic.
López-Longo et al6 studied 128 patients with SLE selected from the rheumatology service at their hospital, 17 of whom had SCLE. They found significantly higher incidences of arthritis, nephritis, central nervous system disease, and pleuritis among the 111 patients with SLE and a significantly higher incidence of photosensitivity in the patients with SCLE. Their 2 groups did not differ significantly in age or sex, but they were not matched for these variables.
The purpose of the present study was to provide a prognostic prediction for patients with SCLE. Seventy-six patients with SCLE were included in the study. Controls, selected from patients with SLE who did not have SCLE, were matched for age, sex, and ethnicity. Extensive reviews of medical records were performed, including records from primary care providers and consultant physicians. Patients with SLE had an increased frequency of serositis, hematologic disorders, and anti–native DNA, anti-Sm, and anti-U, RNP antibodies. Patients with SCLE had an increased frequency of photosensitivity. These results show a dissimilar frequency of internal organ involvement and serologic abnormalities and suggest that patients with SCLE are a distinct subset, with less frequent systemic manifestations than comparable patients with SLE followed up in a rheumatology practice. However, our patients were observed in an outpatient setting rather than a hospital setting. Had we selected patients in a hospital setting, we predict that more patients would have had renal, central nervous system, and, possibly, pulmonary disease, as these patients are more often admitted to the hospital.
Accepted for publication December 4, 2001.
This study was supported by the University of Louisville School of Medicine Summer Research Program.
Corresponding author and reprints: Jeffrey P. Callen, MD, 310 E Broadway, Louisville, KY 40202 (e-mail: firstname.lastname@example.org).