Psoriasis severity: commonly used clinical thresholds may not adequately convey patient impact

Abstract

Background Psoriasis severity is usually evaluated using quantitative and qualitative measures, including per cent body surface area (BSA) involvement, the Psoriasis Area and Severity Index (PASI) and the Dermatology Life Quality Index (DLQI), a patient‐reported questionnaire. However, standardized definitions for psoriasis severity categories have not been well established. A PASI of 10 or 12 has remained the minimal severity threshold defining eligibility for psoriasis treatments. In the present study, the validity of this cut‐off was re‐evaluated in the context of quality of life. Objective To determine whether the thresholds commonly used to define moderate psoriasis (PASI of 10–12 and BSA of 10) are supported by patient‐reported DLQI data. Methods A systematic review of randomized controlled trials that enrolled mild or moderate patients published between January 2000 and June 2017 was used to assess correlations between provider and patient‐generated severity at baseline. Results For subject groups with high impact on quality of life (DLQI > 10), the mean weighted BSA was 7.6 (Range: 7.1–8.4) and the mean weighted DLQI was 11 (Range: 10.2–12.2). Similarly, the mean weighted PASI for patients with DLQI > 10 was 8.7 (Range: 7.1–10.1) and the mean weighted DLQI was 10.9 (Range: 10.1–12.2). Conclusion Patients with PASI or BSA scores less than 10 can have major quality of life impairment. In general, the objective measures of BSA and PASI alone, when excluding DLQI, may not fully capture the impact of disease severity.

Psoriatic Foot Involvement is the Most Significant Contributor to the Inconsistency Between PASI and DLQI: A Retrospective Study from China

“…Besides, we found that PASI and DLQI have almost no correlation between values of DLQI >10 from our real-world data (r=0.16, P<0.001), which in accordance with one study reported that patients with DLQI >10 also reported PASI mostly lower than 10. 8 However, there are also some studies that reported a good correlation between PASI and DLQI. The possible reason for this is that only patients with PASI >10 were allowed to enter clinical trials.…”

“… 7 However, in light of existing literature, PASI was not a comprehensive indicator of disease severity, and the importance of the DLQI is underestimated. 8 If the patient was assessed solely based on PASI, according to the “Rule of Tens”, patients were classified as “mild-to-moderate”. They only received topical therapy, even if their DLQI showed severe effects.…”

Evaluation of a One-step Dose Reduction Strategy of Adalimumab, Etanercept and Ustekinumab in Patients with Psoriasis in Daily Practice

“…Mahil et al ( 20 ) recently stated that PASI ≤2 and PGA clear/almost clear are relevant for treat to target strategies. In our opinion however, not only disease activity, but also QoL, should be taken into account, as it might differ among patients as to which PASI scores are acceptable ( 21 ). Therefore a low DLQI was a prerequisite, apart from PASI.…”

Pro‐inflammatory versus anti‐inflammatory cytokines in psoriatic patients (case–control study)

“…Disease severity is usually assessed clinically utilizing tools like PASI, which has some limitations and subjectivity. Clinician prescribes the treatment based on the severity of PsO, aiming that patient achieves longer remission period and better quality of life 7 …”

“…Clinician prescribes the treatment based on the severity of PsO, aiming that patient achieves longer remission period and better quality of life. 7 Biomarkers for diagnosis and prognosis of PsO help establish disease severity and monitor the therapy. 8 Studies have demonstrated that Th1/Th2 and Th17/T-reg cells and their associated cytokines have significant roles in the pathogenetic process of PsO.…”