The product of the physician global assessment (PGA) and body surface area (BSA) can be used to evalute the severity of psoriasis. The authors are from the University of Utah, the University of Leeds, Boston University and the University of Pennsylvania.

Patient selection: psoriasis



(1) physician global assessment (below)

(2) percent of body surface area involved by psoriasis (from 0 to 100)


Physician global assessment is based on the average of:

(1) erythema (E), measured from 0 to 5

(2) induration (I), measured from 0 to 5

(3) desquamation (D), measured from 0 to 5



= (SUM(3 parameters)) / 3


product of PGA and BSA =

= (PGA) * (percent BSA involved)



• minimum score: 0

• maximum score: 500

• The higher the score the more severe the psoriasis.

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