Nail Lichen Planus Severity Index (NALSI): A Novel Severity Score for Nail Lichen Planus.

Abstract

Clinical challenge Rigorous data on treatment options in nail lichen planus (LP) is lacking and even the existing studies do not offer robust scientific evidence.[1] This is primarily due to lack of a comprehensive severity scoring tool for enabling consistent, comparative and thorough evaluation. It is unlike nail psoriasis, where nail psoriasis severity index (NAPSI) is a commonly used objective, validated tool for assessing nail disease severity and response to treatment.[2] We propose a nail severity score for nail LP which takes into account the peculiarities of this disease e.g., only few features being responsive to therapy; presence of scarring and irreversible changes; and extensive involvement of the nail unit including nail folds. Solution The nail lichen planus severity index (NALSI) is to be scored in four quadrants per nail, like NAPSI where two imaginary lines, perpendicular to each other are drawn. We score nail matrix, nail bed, and nail fold features per quadrant. A score of 0 or 1 is assigned based on the absence or presence of nail matrix disease features [longitudinal ridging/fissuring, longitudinal melanonychia, thinning/thickening of the nail plate, trachyonychia, red/mottled lunula]; nail bed features [diffuse/longitudinal erythema, discoloration (yellow, black, or dyschromia), onycholysis and/or subungual hyperkeratosis, bullous/erosive lesions]; or nail fold features [pigmentation, swelling, LP lesions, and ragged cuticle] [Figure 1; Table 1]. Thus, a maximum score of 3 per quadrant and 12 per nail is possible. In addition, irreversible changes [dorsal pterygium, atrophy, anonychia, or disappearing nail bed] are recorded separately with the English alphabet ‘I’ (for irreversible) being added to the final score [Figure 2]. Thus, the worst possible score would be 12-I per nail and nails without the “I” score could be chosen for comparing treatment efficacy. NALSI can be an objective and simple scoring system estimating the extent of involvement and location of diseases within the nail unit, and is subject to change with both the progression of disease or its resolution with or without treatment.Figure 1: Clinical picture of nail lichen planus showing the Nail Lichen planus Severity Index (NALSI) scoring. Each small box in each of the four quadrants is scored as 1 (if any one of the nail matrix/nail bed/nail fold feature is present) or 0 (if no nail matrix/nail bed/nail fold feature is present). The score for this nail is 10Table 1: Parameters to be Recorded in Nail Lichen Planus Severity Index (NALSI) ScoringFigure 2: Clinical picture of nail lichen planus showing the Nail Lichen planus Severity Index (NALSI) scoring. Each small box in each of the four quadrants is scored as 1 (if any one of the nail matrix/nail bed/nail fold feature is present) or 0 (if no nail matrix/nail bed/nail fold feature is present). The score for this nail is 8-IFinancial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.