[The Role of Nailfold Capillaroscopy in Raynaud's Phenomenon and Autoimmune Diseases].

Connective tissue diseases are systemic autoimmune disorders for which diagnosis is often delayed owing to nonspecific early clinical manifestations. However, Raynaud's phenomenon is a common and early symptom that prompts etiological evaluation. In this context, nailfold capillaroscopy plays a pivotal role. It enables the detection of characteristic microvascular abnormalities, particularly the scleroderma pattern, which is strongly associated with systemic sclerosis and included in both classification and early diagnostic criteria. This review outlines the principles of capillaroscopy interpretation, its diagnostic and predictive value in systemic sclerosis, and its complementary role in other connective tissue diseases, even in the absence of acrosyndrome.