Disease severity measures in a population of psoriasis patients: the symptoms of psoriasis correlate with self-administered psoriasis area severity index scores.

Because of the difficulty and expense of objectively measuring psoriasis severity, very little information exists on the severity of psoriasis in populations. We determined severity in a psoriasis patient population using the validated self-administered psoriasis area and severity index (SAPASI). This population consisted of 578 university dermatology clinic psoriasis patients, and data were analyzed from 317 (55%) questionnaire respondents. The majority of our sample was women (57%), and non-Caucasians represented a larger portion (8 %) in our sample compared with some previous studies. In our population, the reported frequencies of skin and joint symptoms were as follows: pruritus (95 %), skin burning (81 %), joint pain (69%), arthritis (51%), and psoriatic arthritis (20%). The SAPASI was significantly associated with severity of pruritus, burning, joint pain, and psoriatic arthritis. There was a significant negative correlation between the number of treatments employed and the SAPASI. This study provides results of a detailed measurement of the severity of psoriasis in a psoriasis patient population and relates this severity to population characteristics.