Nailfold capillary alterations in pediatric asthma: evidence of peripheral microvascular involvement.

Background

Airway vascular remodeling is well described in asthma, but whether it extends to the peripheral microcirculation is unknown. Nailfold videocapillaroscopy (NVC) allows non-invasive assessment of the microvasculature.

Objective

We aimed to evaluate NVC findings in children with asthma and their associations with disease characteristics.

Methods

This single-center, cross-sectional study was conducted in children aged 8-18 years with asthma at a tertiary pediatric allergy clinic. NVC was performed at 200 × magnification per the EULAR protocol. Findings were compared with age-specific reference values from healthy children using identical methodology.

Results

Thirty-six children with asthma (mean age 12.01 ± 2.66 years; 66.7% male) were enrolled. Versus healthy references, patients had lower capillary density (p < 0.0001), with greater capillary loop diameter (p = 0.03) and width (p < 0.001). Dilated and tortuous capillaries were also more frequent (p < 0.003). Capillary density correlated inversely with BMI SDS (r = -0.33, p = 0.047). Moderate asthma was independently associated with lower capillary density (p = 0.03). Non-inhalant-sensitized patients had lower capillary density (p = 0.02), with greater capillary loop diameter (p = 0.01) and intercapillary distance (p = 0.03). Microhemorrhages (p < 0.01) as well as non-specific patterns (p = 0.02) were also more frequent in this group. Neither giant capillaries nor a scleroderma pattern was detected in any participant.

Conclusion

Children with asthma show distinct peripheral microvascular alterations on NVC, more pronounced with greater severity, higher BMI, and a non-atopic phenotype. NVC may enable non-invasive vascular phenotyping in pediatric asthma.