Psoriasis: Epidemiology, Potential Triggers, Disease Course

Worldwide prevalence rates of psoriasis range from 0.6 to 4.8 %. The disease tends to have a bimodal distribution of onset with the major peak occurring at age of 20–30, and a later smaller peak occurring at age of 50–60. While there are many potential triggers of psoriasis, infections are an important trigger and up to half of children with psoriasis have an exacerbation within 2 weeks following an upper respiratory infection. Psychological distress is a causative or maintaining factor in disease expression for many patients with psoriasis. Other well-documented triggers for flares include trauma, alcohol and smoking, as well as obesity. Plaque psoriasis is usually chronic with intermittent remissions. Plaques may persist for months to years at the same locations; however, periods of complete remission may occur.