A cross-sectional study of the distribution of psoriasis subtypes in different ethno-racial groups

Skin of colored patients with psoriasis are more likely to remain undiagnosed and experience a greater impact on quality of life than their white counterparts. A better understanding of the ethno-racial differences in the presentation of psoriasis can help address these disparities. To compare the prevalence of psoriatic subtypes (plaque, guttate, pustular, erythrodermic, palmoplantar, and inverse) and lesion locations in Caucasian, Asian, and Hispanic/Latino patients, we analyzed cross-sectional, patient-reported, physician-reviewed survey data from 882 adult and 16 pediatric psoriasis patients seen at the University of California, San Francisco Department of Dermatology between 2006 and 2016. Multivariate logistic regression was used to compare the prevalence of psoriasis subtypes and lesional distributions amongst the ethno-racial groups. Asians and Hispanics/Latinos had higher odds of having pustular psoriasis compared to Caucasians (OR=4.36 [95%CI: 1.24-17.62], P=0.026; and OR=5.94 [95%CI: 1.03-31.03], P=0.036, respectively). Asians also had a higher frequency of erythrodermic psoriasis (OR=5.56 [95%CI: 1.41-27.17], P=0.018), but a lower frequency of inverse psoriasis compared to Caucasians (OR=0.26 [95%CI: 0.06-0.80], P=0.036). These differences may relate to genetic or environmental factors or access to care. Clinician awareness of ethno-racial differences in psoriasis subtype and lesion location can facilitate earlier diagnosis and therapeutic intervention.