Revealing Microvascular Involvement in Pediatric Localized Scleroderma Through Nailfold Capillaroscopy.

Background/Objectives: Juvenile localized scleroderma (jLoS) is a chronic inflammatory disorder with skin and subcutaneous tissue involvement. Microvascular alterations are thought to contribute to its pathogenesis. This study aimed to investigate microvascular alterations in children with jLoS using nailfold capillaroscopy (NFC) and to compare the capillaroscopic findings between patients and healthy controls. Methods: A total of 13 children diagnosed with jLoS and 16 age- and sex-matched healthy controls were enrolled. Capillaroscopic assessment included capillary density, tortuosity, dilatation, disorganization, branching, and neoangiogenesis. Dilated and giant capillaries, hemorrhages, avascular areas, and capillary loss were evaluated. The Microangiopathy Evaluation Score (MES) was used to semi-quantitatively assess capillary loss, disorganization, and ramifications. Disease activity and damage were evaluated using the modified Localized Scleroderma Skin Severity Index (mLoSSI) and the Localized Scleroderma Damage Index (LoSDI), respectively. Functional status was measured via the 6 min walk test (6MWT). Results: Plaque morphea was the most common subtype (61.5%), and antinuclear antibody (ANA) positivity was present in 53.8% of patients. Compared to controls, jLoS patients exhibited significantly more frequent capillaroscopic abnormalities, including increased tortuosity, crossing, dilatation, and neoangiogenesis (p < 0.05). Capillary density, length, arterial limb width, apical loop width, and disorganization scores were significantly higher, while intercapillary distance was lower in jLoS patients (p < 0.05). No avascular areas or giant capillaries were observed. MESs were similar between groups. Conclusions: NFC revealed significant microvascular alterations in jLoS patients, supporting its utility as a non-invasive tool for early vascular assessment in localized scleroderma.