More people with psoriasis later get psoriatic arthritis than previously thought.
The number of patients with psoriasis who go on to develop psoriatic arthritis (PsA) is considerably higher than has previously been estimated, a prospective cohort study found.
Among patients enrolled in the Toronto Psoriasis Cohort, the annual incidence of PsA was 2.7 (95% CI 2.1-3.6) per 100, whereas an earlier study found a cumulative incidence of only 5.1% 20 years after the onset of psoriasis, according to Dafna D. Gladman, MD, of Toronto Western Hospital, and colleagues.
This suggests that “a significant proportion of psoriasis patients suffer from unrecognized PsA,” the researchers observed online in Arthritis & Rheumatology.
Epidemiologic studies have demonstrated that most patients who develop PsA had the skin manifestations long before the joint involvement appeared.
“Therefore, patients with psoriasis may serve as a preferred target population for investigating the epidemiology of PsA and for identifying markers of high risk for the disease,” Gladman and colleagues wrote.