Clinical features of nail involvement in patients with psoriasis vulgaris

Abstract

Objective To investigate the prevalence and clinical features of nail involvement in patients with psoriasis vulgaris, and to explore its relationship with clinical manifestations, laboratory findings and metabolic syndrome. Methods Clinical data were collected from 315 outpatients with psoriasis vulgaris who visited the Department of Dermatology, Peking Union Medical College Hospital between September 1, 2011 and April 1, 2014, and retrospectively analyzed. The prevalence and clinical features of nail involvement in patients with psoriasis vulgaris, as well as its relationship with clinical manifestations, laboratory findings and metabolic syndrome were assessed. Results Of 315 patients with psoriasis vulgaris, 156 (49.5%) had nail involvement. The most common nail abnormality was pitted nails (57.7%, 90/156). Moreover, subungual hyperkeratosis (37.8%, 59/156), longitudinal ridges (34.0%, 53/156) and onycholysis (28.2%, 44/156) were also common, while oil-drop patches (12.8%, 20/156) and onychodystrophy (3.8%, 6/156) were relatively uncommon. Compared with patients without nail involvement, those with nail involvement showed longer disease duration (> 10 years) and more severe conditions (psoriasis area and severity index [PASI] > 10) (χ2 = 8.234, 14.200, respectively, both P < 0.01). PASI scores were also significantly higher in patients with nail involvement than in those without (M [P25, P75]: 9.10 [3.88, 18.38] vs. 4.35 [2.50, 11.28], W = 21 350.50, P < 0.001). In addition, patients with nail involvement showed significantly larger areas of psoriatic lesions in the scalp, upper limbs, trunk and lower limbs than those without nail involvement (W= 21 744.0, 23 135.0, 22 743.5, 22 797.0, all P < 0.01), and nail involvement was significantly associated with lesional areas in the scalp (rc c = 0.224, P = 0.01). There was no significant difference in the prevalence of metabolic syndrome between patients with and without nail involvement (9.0% [13/145]vs. 6.5% [10/154], χ2 = 0.643, P = 0.423). However, there was no evidence for the association of nail involvement with gender, family history, the age at onset, metabolic indices, body mass index (BMI) of, or laboratory findings from, patients with psoriasis. Conclusion Nail involvement is common in patients with psoriasis vulgaris, and is closely associated with clinical course and severity of psoriasis. Key words: Psoriasis; Nail diseases; Case-control studies