Periods of psoriatic arthritis onset and diagnosis in Russian patients with moderate to severe psoriasis (according to psoriasis patient registry)

Background: Early detection of psoriatic arthritis in patients with psoriasis remains an unmet medical need. Early diagnosis and treatment initiation in patients with psoriatic arthritis decreases the risk of adverse outcomes and improves patients quality of life. Aims: to describe a period between psoriasis and psoriatic arthritis onset and a period between psoriatic arthritis onset and diagnosis in Russian patients with moderate to severe psoriasis. Materials and methods: analysis of data from the psoriasis patient registry. Patients aged 18 years and older with an established diagnosis of psoriasis and psoriatic arthritis were included in the analysis. Exclusion criteria: no data on timing of psoriatic arthritis onset or diagnosis. Results: sample size for the descriptive characteristic of period between psoriasis and psoriatic arthritis onset was 891 patients; sample size for the descriptive characteristic of period between psoriatic arthritis onset and diagnosis was 849 patients. Psoriatic arthritis onset preceeded cutaneous manifestation of psoriasis in 2.5% of patients. Concurrent onset of cutaneous psoriasis and psoriatic arthritis (within one year) had 10.7% of patients. In 86.8% of patients, cutaneous manifestation of psoriasis preceded manifestation of psoriatic arthritis. Exclusively of patients with psoriatic arthritis developed before or concurrently with cutaneous manifestation of psoriasis, the mean duration of period between psoriasis and psoriatic arthritis onset was 13.7 10.3 years, the median [IQR] 12 [6-19] years. In 24% of patients with psoriatic arthritis the was 1 year or more after its onset. On average, in this subgroup of patients, psoriatic arthritis was diagnosed 3.95.0 years after the signs and/or symptoms onset. Median [IQR] of period between psoriatic arthritis onset and diagnosis was 2 [1-4.5] years. Conclusions: a diagnostic delay in 24% Russian patients with psoriatic arthritis is one year or more. The average delay in diagnosis of psoriatic arthritis is about 4 years.