Evidence that systemic therapies for psoriasis may reduce psoriatic arthritis occurrence

Contemporary biologic therapies for psoriasis are independently licensed for psoriatic arthritis (PsA). Since skin disease generally predates PsA and PsA has a subclinical phase, we investigated the pattern of PsA evolution in psoriasis treated with biologic agents compared to other medications including oral therapy, topical agents or no treatments.

A retrospective chart review was performed in psoriasis patients with musculoskeletal symptoms referred for rheumatological assessment. Patients who had a final diagnosis of PsA were identified. The frequency and clinical features of PsA were compared for biologics versus the other strategies.

Between 2015-18, 203 psoriasis patients were referred for musculoskeletal symptoms with 25 on biologics, 31 on non-biologic systemic therapies and 147 on topical/no therapies. A final diagnosis of PsA was similar in all groups (biologics: 36%; non-biologic systemic treatments: 35.4%; none/local treatments: 37.4%). Most patients had musculoskeletal symptoms before systemic therapy initiation but new onset PsA was evident in 12% (3/25) biologics treated patients, 9.6% (3/31) in non-biologic systemic therapy patients and was significantly higher in patients on topical/no therapy (55/147; 37.4%, p<0.001). Among patients with PsA, none of the patients on biologics exhibited dactylitis compared to 28.6% of other systemic treatments and 48.6% of none/local treatments (p=0.046).

New symptoms and signs leading to PsA diagnosis appear to decrease with systemic treatments. The characteristic PsA dactylitis lesion was not evident in the biologic therapy group.