Table 1.

Scoring Criteria of PASI

Symptoms	0	1	2	3	4
Erythema	None	Slightly reddish	Red, not deep	Markedly reddened	Extremely reddened
Scales	None	Very fine scales covering<50%	Fine scales covering>50%	Coarse scales covering>50%	Very coarse scales covering>50%
Thickness	None	Mild 0.25 mm	Moderate 0.5 mm	Severe 1 mm	Very severe 1.25 mm
Area	0=None	1=1%-9%	2=10%-29%	3=30–49%
		4=50–69%	5=70–89%	6=90–100%

Note: PASI adapted from: Fredriksson T, Pettersson U. Severe psoriasis – oral therapy with a new retinoid. Dermatologica. 1978;157(4):238-244.⁴⁶

Abbreviation: PASI, Psoriasis Area and Severity Index.