Background/Purpose: The purpose of this study was to investigate the association between clinical and unltrasonographic features of psoriatic nail disease and to identify specific nail features associated with psoriatic arthritis (PsA).

Methods: Patients with PsA and Psoriasis without arthritis (PsC) were recruited from prospective cohorts in a single centre. Healthy volunteers were also recruited. Subjects with co-existing OA or history of nail trauma were excluded. A detailed nail assessment according to the modified Nail Psoriasis Severity Index (mNAPSI) for the presence of onhycolysis, nail pitting, nail plate crumbling, leukonychia, splinter hemorrhages, nail bed hyperkeratosis and red spots in the lunula was completed for each participant. All participants underwent an ultrasound evaluation of the nail apparatus at each finger with detailed recording of loss of definition of the ventral or dorsal plates, thickness of the nail bed or matrix and the presence of increased vascularity in the nail bed or matrix using a 10-MHz linear array transducer. Doppler signal was standardized with a pulse repetition frequency of 400 Hz, a gain of 20 dB and a low wall filter. Descriptive analyses and comparisons were conducted using Kruskal Wallis for continuous variables and Fisher’s exact test for categorical variables. Logistic regression analyses using GEE model was used to compare between the groups due to repeated observations for each patient. Results: 10 patients were recruited into each group and the results are reported in the following tables:

Table  1-  Demographic Characteristics (n=30) between Controls, PsC and PsA