Nailfold Capillaroscopic Changes in Children with Atopic Dermatitis

Background: This study aimed to evaluate microvascular changes using nailfold capillaroscopy (NFC) in children with atopic dermatitis (AD) and to contribute to the understanding of the disease's pathophysiology. Methods: The study included 71 children diagnosed with AD (33 girls/38 boys, median age 108 months) and 71 healthy controls (40 girls/31 boys, median age 126 months). Disease severity in AD patients was assessed using the SCORing of atopic dermatitis (SCORAD) index. Parameters with NFC evaluated included capillary density, size, morphology (tortuous, bushy), microhemorrhages, avascular areas, shortening, and crossed capillaries. Results: In the atopic dermatitis group, capillary shortening (<100 micrometers) was significantly more common in the AD group (33.8% vs. 8.4%, p < 0.001; OR = 5.53, 95% CI 2.10-14.59), representing the most robust discriminating finding. Tortuous capillaries (>10%) showed a higher prevalence in AD (36.6% vs. 22.5%, Fisher's p = 0.04); however, this difference did not retain statistical significance after age adjustment (ANCOVA p = 0.076). Bushy capillaries were observed exclusively in the AD group (8.4% vs. 0%, Fisher's p = 0.01), whereas microhemorrhages were detected only in controls (8.4% vs. 0%, Fisher's p = 0.02). Given the wide confidence intervals, these findings should be considered exploratory. No significant differences were found in mean capillary count, dilated capillaries, giant capillaries, avascular areas, or crossed capillaries. NFC findings showed no significant correlation with the SCORAD index in mild and moderate AD. In the severe AD subgroup (n = 3), capillary shortening was observed in all three patients; however, given the very small sample size, this observation should be interpreted as preliminary and exploratory. Conclusions: Our study demonstrates that children with AD exhibit characteristic nailfold capillaroscopic changes, most notably reduced capillary length as the most robust discriminating finding, accompanied by the presence of bushy capillaries. Investigating the molecular mechanisms underlying these microvascular changes and their impact on disease prognosis will provide insight into future treatment strategies.