A study analyzing the clinical extent of psoriasis and its association with psychological stress and its comparison with traits in early (< 40 years; n = 44) and late (> 40 years; n = 26) disease onset was conducted. Seventy patients with psoriasis and 70 patients with other dermatoses were included in the analysis. Psoriasis severity was determined by the Psoriasis Area and Severity Index (PASI). The Psoriasis Life Stress Inventory (PLSI) was significantly correlated with the clinical extent of psoriasis and other measures of psychological distress. Patients with late-onset disease had more prominent depressive symptoms on the Beck Depression Inventory (BDI) versus early-onset patients. On the Minnesota Multiphasic Personality Inventory-201 (MMP-201), ...