Psoriatic nail involvement in Malaysia: A 14-year registry review (2007-2020).

Nail psoriasis affects 20% to 30% of psoriasis patients and is an early predictor of psoriatic arthritis (PsA). We evaluated the prevalence, clinical characteristics, and impact on quality of life of patients with nail psoriasis. We conducted a multicenter retrospective cohort study of patients registered with The Malaysian Psoriasis Registry from January 1, 2007 to December 31, 2020. Of the 24,147 patients, 13,081 (54.2%) had nail psoriasis. Patients with nail psoriasis had later onset of psoriasis (34.0 ± 16.6 years vs 32.9 ± 17.6 years, P < .001) and longer disease duration (11.4 ± 10.5 years vs 8.5 ± 9.4 years, P < .01), with a man-to-woman ratio of 1.2:1. They were more likely to have a family history of psoriasis, cardiometabolic diseases, smoking history, higher body mass index, severe disease, PsA, face and scalp involvement, and higher mean Dermatology Life Quality Index scores (9.36 ± 6.84 vs 8.87 ± 6.60). Systemic treatment and biologics were more commonly prescribed in this cohort (25.0% vs 13.2%, P < .001). Overall, 54.2% of the Malaysian Psoriasis Registry patients had nail involvement. Nail psoriasis was associated with longer duration of psoriasis, older age of onset, male sex, and a family history of psoriasis. It proved to be an important predictor for PsA, severe psoriasis, face and scalp involvement, increased cardiometabolic risk, and a greater impairment of quality of life.