Kaur et al reported the Lichen Planus Severity Index (LPSI) to evaluate a patient with lichen planus. This can be used initially and to monitor the response to interventions. The authors are from the Krishna Institute of Medical Sciences in India.
Patient selection: lichen planus
Parameters)
(1) percent of body surface area involved (using the rule of 9)
(2) number of each of the 5 types of skin lesions
(3) multiplication factor for each of the 5 subtypes
5 types of skin lesions
(1) erythematous papules (Ep)
(2) violaceous papules (Vp)
(3) violaceous plaques (Vpl
(4) hyperpigmented hypertrophic papules and plaques (Hp)
(5) post-inflammatory hyperpigmentation (PIH)
|
Percent of BSA
|
Body Surface Area Factor
|
|
<= 20%
|
1
|
|
21 to 40%
|
2
|
|
41 to 60%
|
3
|
|
61 to 80%
|
4
|
|
> 80%
|
5
|
total number of skin lesions =
= SUM(number of each subtype)
percent for each subtype =
= (number for subtype) / (total number) * 100%
|
Percent of Total
|
Area Involving Factor
|
|
<= 25%
|
1
|
|
26 to 50%
|
2
|
|
51 to 75%
|
3
|
|
> 75%
|
4
|
|
Percent of BSA
|
Multiplication Factor
|
|
Hp
|
4
|
|
Vpl
|
3
|
|
Vp
|
2
|
|
Ep
|
1
|
|
PIH
|
0
|
subscore for each type of skin lesion =
= (area involving factor) * (multiplication factor)
final LPSI =
= (SUM(all 5 subscores)) * (body surface area factor)
Interpretation:
• minimum LPSI: 0
• maximum LPSI: 80 (practically the maximum seen clinically is 64).
• The higher the LPSI the greater the clinical severity.
