Cold fingers under the lens: unveiling microvascular differences between children with primary Raynaud's phenomenon...

This study aimed to evaluate capillaroscopic findings in children with Raynaud's phenomenon (RP) referred to a paediatric rheumatology clinic and compare them to healthy controls to identify RP-related patterns.

Sixty-six patients aged 0-18 years with RP and 65 age- and sex-matched healthy controls were included. Standardized capillaroscopic assessments followed the 2020 recommendations of EULAR study group on microcirculation in rheumatic diseases. Capillaroscopic patterns of 62 primary RP patients were compared with controls.

Two patients were diagnosed with systemic sclerosis and two with systemic lupus erythematosus. Among 62 primary RP patients (median age 14.92 years, 62.9% female), antinuclear antibody positivity was 11.29%. Capillaroscopy revealed increased apical loop diameter (18.74 ± 4.40 vs. 15.20 ± 2.98, P < .001), dilated capillaries (82.3% vs. 15.40%, P < .001), abnormal capillaries (53.2% vs. 18.5%, P < .001), microhemorrhages (17.7% vs. 1.5%, P = .002) in primary RP patients compared to controls. The predominant pattern was non-specific (56.5%) in RP patients and normal pattern in controls (87.7%, P < .001). No correlation was found between capillaroscopy patterns and antinuclear antibody positivity or medication use.

Patients with primary RP showed a unique capillaroscopy pattern. Follow-up studies are needed to assess the proportion who may develop secondary RP and how capillaroscopic findings evolve.