NAPSI (Nail Psoriasis Severity Index)
Nail Psoriasis Severity Index, per target nail (Rich & Scher 2003): matrix (0-4 quadrants) + bed (0-4 quadrants) = 0-8; higher = more nail involvement.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Nail matrix — quadrants involved
- 3
- Nail bed — quadrants involved
- 2
Result: Nail Psoriasis Severity Index 5 of 8 for this nail — matrix 3, bed 2.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- 0-8 per nail
- Matrix (0-4 quadrants) + bed (0-4 quadrants). Sum involved nails for the patient total (0-80 fingernails, 0-160 all 20). No official bands. A grading index, not a diagnosis.
What you enter
- Nail matrix — quadrants involved (0-4)
- Nail bed — quadrants involved (0-4)
How this is calculated
Rich P, Scher RK. Nail Psoriasis Severity Index: a useful tool for evaluation of nail psoriasis. J Am Acad Dermatol. 2003;49(2):206-212. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.