RESUMO
BACKGROUND: Data regarding the prevalence of chronic spontaneous urticaria (CSU) in childhood-onset systemic lupus erythematosus (cSLE) patients and possible associated factors are limited to a few case reports. The objectives of this study were to assess CSU in a large cSLE population, in order to evaluate the demographic data, clinical manifestations, disease activity/damage, laboratory abnormalities and treatment. METHODS: A retrospective multicenter cohort study (Brazilian cSLE group) was performed in 10 Pediatric Rheumatology services and included 852 cSLE patients. CSU was diagnosed according to the guidelines of the European Academy of Allergy and Clinical Immunology, the Global Allergy and Asthma European Network, the European Dermatology Forum and the World Allergy Organization. Patients with CSU (evaluated at urticaria diagnosis) and patients without CSU (evaluated at the last visit) were assessed for lupus clinical/laboratory features and treatment. RESULTS: CSU was observed in 10/852 cSLE patients (1.17%). The median of cSLE duration at urticaria diagnosis was 0 (-3 to 5) years. Comparison of cSLE patients with and without CSU revealed a greater frequency of constitutional symptoms (40 vs. 8%, p = 0.006), reticuloendothelial system involvement (30 vs. 3%, p = 0.003), mucocutaneous (90 vs. 28%, p < 0.0001) and musculoskeletal manifestations (50 vs. 6%, p < 0.0001) and methylprednisolone pulse therapy use (60 vs. 9%, p < 0.0001) in the former group. The frequency of immunosuppressive treatment was lower in patients with CSU (p = 0.018). The median SLE Disease Activity Index 2000 (12 vs. 2, p < 0.0001) and erythrocyte sedimentation rate (40 vs. 19 mm/1st hour, p = 0.024), was higher in patients with CSU. CONCLUSIONS: To our knowledge, this is the first study with evidence that CSU may be linked to cSLE. We also demonstrated that this particular skin manifestation occurs predominantly at disease onset and is associated with lupus moderate/high disease activity without major organ involvement.