THE AGE FACTOR IN NAILFOLD VIDEOCAPILLAROSCOPY IN SYSTEMIC SCLEROSIS: A HYPOTHESIS

Systemic sclerosis (SSc) is characterized by immune-mediated microangiopathy and fibrosis, and nailfold videocapillaroscopy (NVC) is central to diagnosis, risk stratification, and follow-up. Capillary density increases until approximately the age of 10, after which the trend diminishes in older children and adolescents. Additionally, nonspecific loop irregularities and a rise in loop diameter, including tortuosity, become more prevalent as age increases. Aging leads to non-specific alterations (slight reductions in density, mild dilations, and tortuosity); however, it does not produce the characteristic abnormalities (including giant capillaries, avascular areas, and neoangiogenesis) associated with SSc. Nonetheless, it is essential to consider age when assessing standard NVC evaluations and semi-quantitative scoring in SSc to enhance diagnostic precision and minimize misclassification. This hypothesis posits that incorporating age adjustment—via reference centiles or z-scores—into the interpretation of continuous NVC measures will improve diagnostic accuracy and reduce misclassification without diminishing the rule-in weight of hallmark SSc features.