Vessel resistance to blood flow in the nailfold in patients with psoriasis: a prospective case–control echo Doppler-based study

Summary Background  Psoriasis is a disease in which endothelial cells seem to play an important pathogenic role. No report published to date has examined nail vascularity in patients with psoriasis. Objectives  To evaluate the vascularity in the nails of patients with psoriasis treated with classic and biologic therapies for comparison with disease-free controls, and to evaluate whether there are differences in nail vascularity among patients with and without nail involvement. Methods  We performed a prospective study with two cohorts comprising 23 patients with moderate-to-severe psoriasis and 23 controls without psoriasis. We measured the nailfold vessel resistance index (NVRI) in each subgroup. Results  We found significant differences in the NVRI between patients and controls (P < 0·001). Among patients with psoriasis, those with nail involvement showed a higher mean ± SD NVRI (0·58 ± 0·10) than those without (0·52 ± 0·45). Conclusions  Psoriasis decreases the blood flow in nails, suggesting that this skin disease confers an independent risk for microvascular changes. This outcome may be associated with greater risk of nail-related signs.