Nailfold capillary abnormalities predict PAO in palmoplantar pustulosis

Abnormalities of nailfold capillary (NHC) appear predictive of pustulotic arthro-osteitis (PAO) in patients with palmoplantar pustulosis (PPP), while their degree indicators may predict disease severity, according to a prospective cohort study.

A total of 102 PPP patients were included in this study, which assessed the clinical significance of NPC changes in PPP. The investigators analysed the associations of NFC abnormalities, including nailfold bleeding and enlarged capillaries, with PAO prevalence, the incidence of new PAO, and serum levels of cytokines.

Of the PPP patients, 50 had PAO and 52 had no PAO. Both nailfold bleeding (92.0 percent vs 50.0 percent; p<0.0001) and enlarged capillaries (94.0 percent vs 50.0 percent; p<0.0001) occurred more frequently among patients with vs without PAO.

Moreover, PPP patients without PAO were prospectively observed prior to their development of PAO (mean 28 months).

Multivariate analysis revealed that NFC abnormalities significantly predicted PAO development (nailfold bleeding: hazard ratio [HR], 3.37, 95 percent confidence interval [CI], 1.13‒10.07; enlarged capillaries: HR, 3.37, 95 percent CI, 1.13‒10.07). On the other hand, guselkumab use was preventive of PAO development (HR, 0.093, 95 percent CI, 0.012‒0.76).

Notably, the degree of NFC abnormalities was predictive of PAO severity and serum cytokine levels.

The study was limited by participants who were all Japanese.

“PAO is one of the most serious comorbidities associated with PPP,” said the investigators.