Olsen et al developed the Severity of Alopecia Tool (SALT) to evaluate the degree of alopecia affecting the scalp. This is based on the visual aid of Olsen and Canfield.
Region of the Scalp
Percent of Scalp Area
top of the head
40%
back of the head
24%
left side
18%
right side
18%
subscore for each region =
= (percent hair loss in region) * (percent of scalp surface area)
total SALT score = percent of scalp showing hair loss =
= SUM(subscores for the 4 regions)
Percent Hair Loss
Subgroup
0%
S0
1 to 24%
S1
25 to 49%
S2
50 to 74%
S3
75 to 95%
S4a
96 to 99%
S4b
100%
S5
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