CUTANEOUS MANIFESTATIONS OF SYSTEMIC AUTOIMMUNE DISEASES

Introduction: Cutaneous manifestations represent one of the most frequent and clinically informative components of systemic autoimmune diseases, often reflecting complex immune dysregulation that extends beyond the skin. In many autoimmune conditions, dermatological findings may precede systemic involvement, emerge during disease flares, or persist as markers of chronic immune activation. These manifestations provide a visible and accessible interface through which systemic disease activity, severity, and progression may be inferred. As such, careful evaluation of the skin can play a pivotal role in early diagnosis, prognostic stratification, and longitudinal monitoring of patients with systemic autoimmune disorders. Objective: The primary objective of this systematic review was to comprehensively synthesize contemporary evidence regarding the spectrum and clinical relevance of cutaneous manifestations in systemic autoimmune diseases. Secondary objectives included evaluating the diagnostic value of specific skin phenotypes, assessing their association with systemic organ involvement and disease activity, analyzing their prognostic implications for morbidity and mortality, exploring underlying immunopathological correlations, examining their impact on therapeutic decision-making, and identifying methodological gaps and limitations within the current literature. Methods: A systematic search was conducted across PubMed, Scopus, Web of Science, Cochrane Library, LILACS, ClinicalTrials.gov, and the International Clinical Trials Registry Platform. Predefined inclusion and exclusion criteria were applied, prioritizing studies published within the last five years while allowing extension when necessary to ensure adequate representation. Eligible studies were synthesized qualitatively in accordance with PRISMA recommendations, with structured assessment of risk of bias and certainty of evidence to support an evidence-based interpretation of findings. Results and Discussion: Twenty studies met the inclusion criteria, encompassing a broad range of systemic autoimmune diseases, including connective tissue diseases, systemic vasculitides, and overlap syndromes. Across these conditions, specific cutaneous phenotypes consistently correlated with systemic disease activity, internal organ involvement, prognostic outcomes, and patient-reported quality-of-life measures. Skin manifestations such as chronic lupus lesions, dermatomyositis-associated ulcerations, systemic sclerosis-related skin fibrosis, and vasculitic lesions in Sjögren syndrome and systemic vasculitis emerged as clinically meaningful markers of disease severity. Despite consistent trends, heterogeneity in study design, lesion classification, and outcome reporting limited the certainty of evidence in some domains. Conclusion: The available evidence indicates that cutaneous manifestations are not merely ancillary findings but constitute clinically meaningful markers of systemic autoimmune disease activity and prognosis. Their systematic recognition and interpretation can enhance diagnostic accuracy, facilitate early identification of high-risk patients, and inform individualized management strategies. Integration of structured dermatological assessment into multidisciplinary, evidence-based care models is essential to optimize outcomes and improve quality of life for patients with systemic autoimmune diseases.