Itch Improvement Impacts Dermatology Life Quality Index Scores for Eczema, Psoriasis

mprovement in itch is an important predictor of Dermatology Life Quality Index (DLQI) improvements among patients with atopic dermatitis or psoriasis, new findings suggest, highlighting the value of assessing pruritus in clinical trials.¹

These findings were drawn from recent research conducted to expand upon existing research into the effect of itch on quality of life among patients with inflammatory diseases. Wolf-Henning Boehncke, from the division of dermatology and venereology at Geneva University Hospitals in Switzerland, led a post-hoc analysis evaluating such data.

The research team noted the increasing advocacy toward focusing on patients' reported outcomes like itch given its notable impact on life quality. Despite the well-documented research into atopic dermatitis drugs’ effect on itch control, they cited the smaller amount of data on psoriasis treatments’ impact.²

“To better understand the impact of itch on the patients' quality of life in (psoriasis) as well as (atopic dermatitis), we analysed data sets from three Phase III clinical studies, one in (psoriasis) and two in (atopic dermatitis), for which various physician- and patient-reported outcomes were available,” Boehncke and colleagues wrote.¹

Study Design

The research team highlighted the BREEZE-AD1 and BREEZE-AD2 studies and the IXORA-R study, all of which evaluated atopic dermatitis and psoriasis patients, respectively. BREEZE-AD1 and 2 were phase 3 randomized, multicenter, double-blinded trials.

The BREEZE-AD studies involved subjects aged 18 and older diagnosed with moderate to severe atopic dermatitis and an inadequate topical medication response before screening. The investigators randomly assigned the participants to receive either a placebo or baricitinib at a 1 mg, 2 mg, or 4 mg daily dose over the course of 16 weeks. The research team’s post-hoc analysis was aimed exclusively at the subjects in these 2 clinical studies given the 4 mg dose, as determined by the European Medicines Agency (EMA).

The IXORA-R trial was conducted as a multicenter, 24-week, parallel-group, double-blinded, phase 3 randomized clinical trial evaluating subjects aged 18 years and older with chronic moderate-to-severe plaque psoriasis. The team randomized subjects to be treated with either ixekizumab or guselkumab.

Specifically, participants given ixekizumab were initially treated with a 160 mg dose, followed by an 80 mg dose every 2 weeks from the 2 to 12-week marks. Then, these participants were treated with 80 mg every 4 weeks following. The investigators’ post-hoc analysis was aimed only at participants who had been treated with ixekizumab.

In the investigators’ post-hoc analysis, they looked at the relationship between itch and skin improvements by assessing correlations noted between objective signs of quality of life, disease improvement, and itch severity over the course of 16 weeks.

Clinical outcomes related to atopic dermatitis were evaluated by the proportion of subjects with 75% and 90% improvement in their Eczema Area and Severity Index (EASI75 and EASI90) scores along with the percentage change from baseline (CFB) in subjects’ total EASI scores. In the study assessing psoriasis, the outcomes evaluated by the team included the percentage CFB in participants’ total PASI scores and the percentage of those with 75% and 90% improvement in their Psoriasis Area and Severity Index (PASI75 and PASI90) scores.

Correlations with these clinical outcomes were then done using patient-reported outcomes. Some of these included the mean CFB in their Itch Numeric Rating Scale (NRS), as well as shifts in participants’ DLQI scores such as the DLQI (0/1) response. For the purposes of examining the effect of clinical and Itch NRS improvements on subjects’ DLQI outcomes, the investigators used predictive analyses.

Findings

Overall, the research team’s modeling of real-world data on psoriasis and atopic dermatitis showed that there was an equally valuable role in itch improvements among patients with both skin diseases associated with predicting a DLQI (0/1) response at the 16-week mark.

Additionally, shifts in pruritus seen among those with psoriasis from the point of baseline were reported to have higher correlation to DLQI CFB and DLQI (0/1) response versus PASI75 and PASI90 (0.49 and 0.38 versus 0.32 and 0.33, respectively) at the 16-week mark.

Overall, the investigators found that an important role is plated by itch in patients’ disease burden among those with both psoriasis and atopic dermatitis. This, they suggest, points to itch being under-appreciated in clinical studies related to psoriasis.

“Future directions of research in this field should, among others, include investigating the differences and similarities in the pathogenesis of itch in (psoriasis) versus (atopic dermatitis) and explore the quality of itch in the respective dermatoses (annoying vs. burning),” they concluded.

References

1. ^{Boehncke WH, Reich A, Ständer S, Hernandez J, Mert C, Grond S, et al Itch improvement has a major and comparable effect on the Dermatology Life Quality Index in psoriasis and atopic dermatitis patients. JEADV Clin Pract. 2024; 1–9. https://doi.org/10.1002/jvc2.509.}
2. ^{Müller S, Witte F, Ständer S. [Pruritus in atopic dermatitis-comparative evaluation of novel treatment approaches]. Dermatologie. 2022; 73(7): 538–549.}