Andersen YMF, et al. - The prevalence of palmoplantar pustulosis (PPP) and co-occurring psoriasis was determined in three population-based cohorts. In addition, information on patient demographics and characteristics was explored. Using administrative healthcare registries and insurance databases from the US, Denmark, and Germany, they identified a total of 1435, 751 and 1832 patients with PPP with an estimated one-year prevalence of 0.009%, 0.005%, and 0.08%, respectively. Patients with PPP exhibited the plaque psoriasis prevalence ranging from 14.2% to 61.3%. Possibly due to differences in diagnostics and recording practices, the three studied populations varied in the one-year prevalence of PPP. They observed an overall higher prevalence of psoriatic arthritis among patients with co-occurring psoriasis. Similarly, medication use, especially the use of biologic therapies, was more prevalent in PPP patients with co-occurring psoriasis.