Improvements in Skin and Nail Psoriasis are Positively Correlated across Systemic Psoriasis Therapies

Objective: For clinical scenarios where patients have moderate to severe psoriasis and nail psoriasis, knowing whether skin response is correlated with nail response would provide insight into the relationship between psoriatic skin and nail unit inflammation. The primary objective of this study was to determine if improvement in skin and nail psoriasis across a range of systemic therapies are correlated. Methods: Relevant publications pertaining to systemic therapies approved in the US for psoriasis were identified via PubMed search. Only studies with placebo controls were included. The paired point estimates of the PASI 75 response treatment effect [i.e., the placebo-adjusted PASI 75 response rate] (independent variable) and mean percentage NAPSI improvement for target fingernail treatment effect [also placebo-adjusted] (dependent variable) were calculated for each therapy. Simple linear regression analysis weighted by the standard errors for the independent and dependent variables was performed. Results: Ten paired treatment effects for 4 systemic therapies (apremilast, adalimumab, etanercept, and guselkumab) were obtained. Guselkumab and adalimumab were associated with the greatest nail improvement, and guselkumab was associated with the greatest skin response rate. PASI 75 response rate and mean percentage improvement target fingernail NAPSI were positively correlated (p=0.03), with an R2 value of 0.48. Conclusions: There is significant positive correlation across different therapies between the magnitude of improvement in psoriatic skin and nail disease among patients with moderate-severe psoriasis and clinically significant nail disease.