Routine PEST screening found 61.5% positive for psoriatic arthritis

In a prospective, single-center, nonrandomized controlled study of 117 adults with dermatologist-confirmed psoriasis, 72 patients (61.5%) screened positive for psoriatic arthritis after routine use of the Psoriasis Epidemiology Screening Tool (PEST), significantly increasing detection versus the period before routine screening (P<0.001).

Psoriatic arthritis affects up to 30% of patients with psoriasis, corresponding to nearly 3 million people in the United States. Without timely treatment, up to 20% of patients with psoriatic arthritis may progress to irreversible joint damage and severe functional limitations.

Dermatologists are well positioned to identify the disease early, yet up to 40% of dermatology providers do not routinely screen. The report identifies three recurring barriers:

• Limited visit time
• Lack of training in screening tools
• Uncertainty about next steps

Detection rose after routine screening

The prospective study took place in an outpatient dermatology clinic, where investigators used PEST, described as a validated, low-cost instrument. The 61.5% positive rate was statistically higher than detection before routine screening (P<0.001), but the report did not state the earlier rate, so the finding cannot be expressed as a percentage-point increase.

In logistic regression, pain severity was the only significant predictor of a positive screen (P<0.001). The association does not turn pain into a substitute for screening; it identifies pain severity as the sole factor significantly linked to a positive result in this cohort.

A one-month diet comparison produced a short-term signal

The study paired its screening findings with a treatment comparison among patients who screened positive. Participants chose one of two paths:

• Biologic therapy alone
• Biologic therapy plus a Mediterranean diet intervention

Researchers assessed pain at baseline and at one month, then used one-way ANOVA to compare changes among treatment groups. The analysis evaluated patients treated with guselkumab or secukinumab with and without adherence to the diet.

Guselkumab combined with the Mediterranean diet produced the greatest one-month pain reduction compared with biologic therapy alone. The report gave the comparison as a mean change of 3.13 ± 1.12 (P=0.01).

Because the report does not identify the pain scale, the 3.13 figure cannot be translated into a percentage or a treatment target. It should be read as the study's reported one-month signal rather than a stand-alone measure of long-term disease control.

What does this change for psoriasis care?

For dermatology practices, the findings support making PEST screening routine rather than opportunistic. The study provides a concrete signal for that workflow: implementation accompanied significantly higher detection. The validated, low-cost tool adds a standardized step to ordinary psoriasis visits and may help identify patients who need joint care sooner.

For patients, the study supports discussing a Mediterranean-diet intervention alongside indicated biologic therapy, not substituting diet for medication. The pain-reduction signal was greatest with guselkumab plus the diet at one month; the analysis did not test diet without biologic therapy.

The main limits are the single-center design and patient-selected treatment. Follow-up lasted only one month. Those features make the diet finding an association rather than proof of benefit and leave durability unestablished.

The study also does not show that routine screening or dietary counseling prevents irreversible joint damage. Its contribution is increased detection plus a short-term pain signal that can inform routine psoriasis care and adjunctive lifestyle counseling.

Czerkasij V and colleagues reported the work as Implementing Psoriatic Arthritis Screening and Dietary Interventions in Dermatology Practice: A Prospective Clinical Study in J Drugs Dermatol. 2026;25(11):1033. With larger, longer studies using standardized pain measures and randomized allocation, dermatology practices can test whether this one-month signal persists and whether routine screening changes long-term joint outcomes.