Nail fold capillaroscopy: normal findings in children and adolescents

Capillaroscopy is a simple diagnostic method that permits noninvasive in vivo study of the capillary network. Studies designed to standardize capillary normality in children are limited. This article presents the capillaroscopic findings in healthy children and adolescents, thus making the application of this methodology viable for patients in this age range.

Healthy children were recruited from a private elementary school and junior high school. Nail fold capillaroscopy was performed using a stereomicroscope at 16 times magnification, addressing the following parameters: capillary morphology, capillary enlargement, devascularization, microhemorrhage, and subpapillary venous plexus visibility (PVS). These parameters were related to age, sex, ethnicity, and local periungal conditions.

The sample comprised 329 individuals with mean age of 8.2 years. We observed atypical capillary morphology in 118 of the studied cases (36%), mainly bizarre capillaries in 90 (27%), meandering capillaries in 32 (10%), and bushy capillaries in 20 (6%). The enlarged capillary phenomenon was uncommon, being observed in 30 cases (9%). The number of capillaries per millimeter varied from five to nine. Deletion areas were detected in only seven individuals (2%). The subpapillary venous plexus was not visualized in 13 (4%) cases. Younger children presented higher PVS scores and fewer capillaries/mm as compared with older children. PVS scores were lower in males and in nonwhite children. Other variables were not associated with sex or ethnicity.

The normal nail fold capillary network in children resembles that observed in adults with some differences, such as a lower number of loops per millimeter, a higher PVS score, and a higher frequency of atypical loops. This information is important for the diagnostic evaluation of children in the context of autoimmune rheumatic diseases.