Skin involvement in the catastrophic antiphospholipid syndrome: A review from CAPS registry

ObjectiveTo describe the prevalence, clinical manifestations, histopathological features, and antibody profile associated to skin involvement in patients with catastrophic antiphospholipid syndrome (CAPS).MethodsWe performed a cross-sectional study of the patients included in the "CAPS Registry," a registry developed by the European Forum on Antiphospholipid Antibodies (aPL)1,2 This database contains data from patients with CAPS collected from April 1992 to December 2024. Demographic clinical manifestations, laboratory features (including aPL antibodies), pathological findings in involved skin, and outcome were retrieved.ResultsCutaneous involvement was described in 377 episodes (47%) from 361 patients. A female sex prevalence of 49.4% was observed. The average age was 39.4 (SD ± 17.9) years. The more frequent skin manifestations observed were livedo reticularis (17.6%), skin necrosis (13%), ischemic ulcers (10.4%), skin ischemic (9.7%), skin purpura (7.1%), gangrene (5%), splinter haemorrhages (2.6%), and Raynaud's phenomenon (1.5%). The most frequently affected organs in CAPS episodes with skin involvement were kidneys (72%), lungs (61%), central nervous system (54.5%), and heart (54.4%). Thrombocytopenia and hemolysis features were more common in patients with skin involvement (p < 0.05 for all). Thrombotic microangiopathy was the predominant pathological finding, present in 82 (68.3%) episodes. No difference regarding mortality were found in episodes with or without skin involvement (29.3% vs 32.1%, p = 0.42).ConclusionThe presence of skin involvement in patients with CAPS is frequent. The most frequent manifestations were livedo reticularis and skin necrosis. Skin involvement does not seem to be associated to mortality.