New approach to clinical evaluation of nail lesions in psoriasis

Background. Psoriatic onychodystrophy is difficult to treat being a psoriasis of complex localizations. Possibilities of clinical assessment of nail lesions in psoriasis and efficacy of the performed therapy are currently severely limited due to the laborious process of working with existing indices, which are difficult to be applied in the evaluation of psoriatic onychodystrophy over time. Objective. Study of the prevalence of psoriatic onychodystrophy, as well as a proposal of an own method for assessing its course severity and the treatment efficacy. We have also tried to introduce a new term, namely «psoriatic dyad» to denote the severe course of nail psoriasis. Material and methods. Between 2018 and 2021, 509 patients with the established «psoriasis» diagnosis were examined. Nail lesions in patients with psoriasis were assessed using the psoriatic onychodystrophy severity index (NAPSI). Results. Nail lesions were noted in 133 (59.3%) patients. The most common types of nail lesions were nail pitting (72/54.1%) and «oil drop» symptom together with onycholysis (57/42.8%). Based on the literature data and own research we have developed an algorithm for assessment of the severity of nail psoriasis course — scale of evaluation of therapy and severity of psoriatic onychodystrophy — NAPTSS (Nail Psoriasis Therapy and Severity Score), considering 2 signs of lesion for the nail matrix (nail pitting, Beau’s lines and onychomadesis) and 2 — for the nail bed (longitudinal hemorrhages, «oil drop» symptom and onycholysis). In case of combined lesion of the nail matrix and nail bed, we have proposed «psoriatic dyad» term. Conclusion. Proposed NAPTSS scale is an attempt to create a simple and practical system for assessing nail damage in psoriasis and the efficacy of treatment. We believe that «psoriatic dyad» term is necessary for indicating severe clinical situation of combined lesion both of the nail matrix and of the nail bed.