To the Editor The study by Egeberg et al1 in JAMA Neurology found that rosacea is an independent risk factor for Parkinson disease. This is an interesting finding; however, from an etiologic standpoint, we feel it is important to take into account that rosacea is a diverse condition with several subtypes. The National Rosacea Society Expert Committee2 recognizes the following 4 subtypes of rosacea: erythematotelangiectatic, inflammatory papulopustular, phymatous, and ocular. Patients with each subtype have varying demographics, clinical symptoms, and underlying pathomechanisms. While the authors in this study performed a sensitivity analysis on patients with the ocular subtype,1 they did not differentiate among the other 3 types of rosacea.
He A, Sweren RJ, Kwatra SG. Association Between Rosacea and Parkinson Disease. JAMA Neurol. 2016;73(9):1158-1159. doi:10.1001/jamaneurol.2016.1875