The nail is divided into 4 quadrants (2 proximal, 2 distal).
Each quadrant is graded 0 or 1 based on the absence or presence of psoriatic changes to the nail matrix in that quadrant.
Changes indicative of psoriasis of the nail matrix - one or more of the following:
(1) pitting
(2) leukonychia
(3) red spots in the lunula
(4) crumbling
Each quadrant is graded 0 or 1 based on the absence or presence of psoriatic changes to the nail bed in that quadrant.
Changes indicative of psoriasis of the nail bed - one or more of the following:
(1) oil drop (salmon patch dyschroma)
(2) onycholysis
(3) subungual hyperkeratosis
(4) splinter hemorrhages
total score =
= (number of quadrants showing psoriatic changes in the nail matrix) + (number of quadrants showing psoriatic changes in the nail bed)
Interpretation:
• minimum score: 0
• maximum score: 8
• The higher the score the greater the involvement of the nail.