Psoriasis and psoriatic arthritis in African-American patients--the need to measure disease burden.

Gaps in knowledge exist regarding the clinical characteristics of psoriatic disease in ethnic minority patients. We evaluated validated clinical disease measures of psoriasis and psoriatic arthritis in African-American and Caucasian patients. Adult outpatients with confirmed diagnoses of psoriasis and psoriatic arthritis and seen at four urban academic institutions were eligible for evaluation. Validated patient and physician-reported disease outcome parameters, quality of life measures of psoriasis and psoriatic arthritis, and frequencies of systemic immunosuppressive therapies and patient comorbidities were documented. Psoriatic arthritis was less frequent in African-Americans compared to Caucasians (30 vs. 64.5 %, respectively, p < 0.001); however, African-Americans had more severe skin involvement [Psoriasis Area and Severity Index 8.4 (10.0) vs. Caucasians 5.5 (6.4), p = 0.06], with greater psychological impact and impaired quality of life. Use of biologic therapies was greater in Caucasian patients (46.2 vs. 13.3 % in African-Americans, p < 0.0001); yet, only one in four patients of the study cohort achieved minimal disease activity. Comorbidity was not associated with frequency of immunosuppressive drug use. In order to achieve a target of low disease activity and to reduce ethnic disparities in the care of psoriatic disease, the routine application of measures of disease status is needed.