Prevalence and clinical patterns of psoriatic arthritis in Indian patients with psoriasis

Background: The prevalence and clinical patterns of psoriatic arthritis (PsA) varies in different parts of the world and there is little clinical and epidemiological data from the Indian subcontinent. Aims: Our study was designed to evaluate the prevalence and clinical patterns of PsA in Indian patients. Methods: This was a non-interventional, cross-sectional study, in which 1149 consecutive psoriasis patients seen over 1 year were screened for PsA according to classification of psoriatic arthritis (CASPAR) criteria. Demographic and disease parameters were recorded including Psoriasis Area and Severity Index (PASI), Nail Psoriasis Severity Index (NAPSI), and number of swollen and tender joints. Results: Among 1149 patients with psoriasis, 100 (8.7%) patients had PsA, of which 83% were newly diagnosed. The most common pattern was symmetrical polyarthritis (58%), followed by spondyloarthropathy 49%, asymmetric oligoarthritis (21%), isolated spondyloarthropathy (5%), predominant distal interphalangeal arthritis (3%), and arthritis mutilans (1%). Enthesitis and dactylitis were present in 67% and 26% of cases, respectively. The mean number of swollen and tender joints were 3.63 +/- 3.59 (range, 0-22) and 7.76 +/- 6.03 (range, 1-26), respectively. Nail changes were present in 87% of the cases. The median PASI and NAPSI of the subjects with PsA was 3.6 and 20, respectively. There was no significant correlation of number of swollen/tender joints with PASI or NAPSI. Conclusion: There is a relatively low prevalence of PsA among Indian psoriasis patients presenting to dermatologists. No correlation was found between the severity of skin and nail involvement and articular disease.