Background: The Psoriasis Area and Severity Index (PASI) is used to quantify the extent of the disease, and to evaluate its improvement with treatment. It is considered to be a slow, rough, nonsensitive, and complex tool, with high interobserver variability and low reproducibility.
Objectives and methods: To develop a simpler, more sensitive, and more rapid end-point determination for evaluating the psoriatic condition, and to compare its sensitivity with that of the classic PASI score in psoriatic patients undergoing 4-week climatotherapy at the Dead-Sea (Israel).
Results: This study describes a new, rapid, and simple Psoriasis Assessment Severity Score (PASS), whose readings are spread over a longer scale, making the test more sensitive than PASI, and allow better differentiation.
Conclusions: The comparison between the classic PASI and our new PASS emphasizes the weight of the "sensitivity to change" (responsivity) in selecting a better evaluation method for psoriatic patients.