Nailfold videocapillaroscopy in healthy children and adolescents: description of normal patterns

Abstract

Objective. to describe normal patterns of nailfold videocapillaroscopy (NVC) in healthy children and adolescents

to quantify the relationship between age and capillary dimensions, intercapillary distance and number of capillaries/mm

to evaluate the inter and intraobserver concordance. Methods. Cross-sectional study including 100 healthy participants aged 5 to 18 years. Capillary dimensions (capillary loop length, capillary width and intercapillary distance) and number of capillarieslmm were evaluated in 900 capillaries using stereomicroscope under 100x magnification. Intra and inter observer agreements were tested. Results. The capillary dimensions (mean +/- SD) were: capillary loop length 278.6 +/- 60.3 mu m, intercapillary distance 124.1 +/- 28.1 mu m, capillary width 15.0 +/- 2.6 mu m. Teenagers between 15 and 18 years had longer and more enlarged capillaries than the other age groups (p<0.001 and p=0.012 respectively). We also found a significant increase in the number of capillaries/mm with age (p<0.001). There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width (p<0.001, R=0.796, p<0.001, R=0.368

p=0.004, R=0.285, respectively). There was a good intra and interobserver concordance. Enlarged capillary and avascular areas were present in 11% and 10% of capillaries respectively. A weak negative correlation was found between the intercapillary distance and the number of capillaries/mm (p=0.05

R=-0.20). Conclusion. There is a wide variability in the capillary morphology among healthy individuals. There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width. In addition, NVC has been shown to be a reproducible method.