Comorbid Psoriatic Arthritis Generally Worsens Psoriasis Severity

New survey results from the National Psoriasis Foundation (NPF) show the drastic impact on the quality of life (QoL) for patients with psoriasis and psoriatic arthritis (PsA) compared to patients with psoriasis alone.

Investigators, led by Andrew Blauvelt, MD, found significant impacts on the QoL of patients with both psoriasis and PsA, which supports previous research on the subject, as earlier studies also reported a decrease in QoL and impaired physical function in participants with both diseases.

However, the studies were conducted with small sample sizes. Blauvelt and colleagues chose to perform a larger, national US survey of people with psoriatic diseases to better understand the impact of PsA on human lives worldwide.

The Study

A national population of 1570 people with psoriatic diseases were chosen to participate in the study. Participants were required to contact the NPF between 2017-2019 and self-report a physician-given diagnosis of psoriasis and PsA if applicable.

All respondents were 18 years or older.

The survey included the Patient-Reported Outcome Measurement Information System (PROMIS) Ability to Participate in Social Roles and Activities version 2.0, as well as PHQ-2 and PHQ-9 depression screeners and the Dermatology Life Quality Index (DLQI).

Additionally, standardized t-scores were calculated for Ability to Participate in Social Roles and Activities, which allowed for comparison for the general US population, and Patient-Reported Extent of Psoriasis Involvement (PREPI) was used to collect body surface area (BSA) estimates.

After the respondents completed the survey, 758 (48.3%) reported a healthcare provider diagnosis of psoriasis and PsA, while an nearly equal amount were diagnosed with psoriasis alone (46.9%).Significantly less patients were diagnosed with PsA alone (4.8%).

Respondents were largely Caucasian (86.8%) and female (59.3%) with an average of 53.6 years of age.

Results

Blauvelt and colleagues found that 29.3% of respondents reported limitations in their ability to participate in social roles and activities while 40.6% reported moderate to large effects on QoL due to their skin disease.

In addition to that, 23.4% of respondents experienced depression in the 2 weeks leading up to the survey.

After the investigators adjusted the survey for skin disease severity, age, and number of comorbidities other than depression, the survey shows that participants with psoriasis and PsA experienced worse outcomes compared participants with psoriasis alone.

A decreased ability to participate in social roles and activities and more depressive symptoms in the former group were recorded. However, differences in dermatologic-specific QoL between either group were not statistically significant.

Given the results of the study as well as the likelihood of the development of PsA in people with psoriasis, the investigators urged for screening methods that focused on patients’ mental health.

“These results add to evidence demonstrating the impact of PsA compared with psoriasis alone on mental health, functional ability, and QoL, underscoring the need to screen people with psoriasis for PsA and depression,” the investigators wrote.

An estimated 8.3 million people in the US are affected by the disease, with global rates as high as 125 million.

Additionally, patients with psoriatic diseases experience high comorbidity rates, and an estimated 30-40% develop PsA.

The study, “Decreased quality of life in people with psoriasis and psoriatic arthritis versus people with psoriasis alone: data from a national US survey,” was published online in the British Journal of Rheumatology.