Improvement in body surface area is associated with better quality of life among patients with psoriasis in the Corrona Psoriasis Registry

To the Editor: In an effort to improve care for patients with psoriasis in the United States, the National Psoriasis Foundation recently published recommended treatment goals based on assessment of body surface area (BSA).1Armstrong A.W. Siegel M.P. Bagel J. et al.From the Medical Board of the National Psoriasis Foundation: treatment targets for plaque psoriasis.J Am Acad Dermatol. 2017; 76: 290-298Abstract Full Text Full Text PDF PubMed Scopus (86) Google Scholar Although BSA is a widely accepted measure of disease severity, it does not specifically capture quality of life (QoL). We evaluated the association of BSA with QoL, assessed by the Dermatology Life Quality Index (DLQI), after 6 and 12 months of treatment with systemic therapy among patients in the Corrona Psoriasis Registry.2Strober B. Karki C. Mason M. et al.Characterization of disease burden, comorbidities, and treatment use in a large, US-based cohort: results from the Corrona Psoriasis Registry.J Am Acad Dermatol. 2018; 78: 323-332Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar This study included 665 patients who had complete data on BSA at their enrollment and 6- and 12-month visits among the 2825 patients enrolled in the Corrona Psoriasis Registry between April 2015 and May 2017. The relative change in DLQI, a composite measure evaluating the effect of the disease on QoL,3Finlay A.Y. Khan G.K. Dermatology Life Quality Index (DLQI)—a simple practical measure for routine clinical use.Clin Exp Dermatol. 1994; 19: 210-216Crossref PubMed Scopus (3160) Google Scholar and the proportion of patients with DLQI of greater than 5 at enrollment achieving DLQI 0/1 was determined at 6 and 12 months. BSA was reported as the percent skin involvement on a scale of 0% to 100%, with psoriasis severity classified as mild (BSA ≤ 3%) and moderate to severe (BSA > 3%).1Armstrong A.W. Siegel M.P. Bagel J. et al.From the Medical Board of the National Psoriasis Foundation: treatment targets for plaque psoriasis.J Am Acad Dermatol. 2017; 76: 290-298Abstract Full Text Full Text PDF PubMed Scopus (86) Google Scholar Of the 665 patients with psoriasis who met the study criteria, 306 (46%) patients had mild BSA, and 359 (54%) patients had moderate to severe BSA at enrollment. Among patients with BSA of greater than 3% at enrollment, 45 (12%) achieved BSA of 0%, 49 (14%) achieved BSA of 1%, 76 (21%) achieved BSA of 2% to 3%, and 189 (53%) remained at BSA greater than 3% at the 6-month visit. Relative change in DLQI increased (indicating improvement in DLQI) as BSA decreased (indicating improvement in BSA) (Fig 1). At the 6-month visit, patients who were in the BSA >3% group had a worsening in DLQI of 47%, whereas patients who achieved a BSA of 0% had a 57% improvement in DLQI score. At the 12-month visit, 54 (15%) achieved BSA of 0%, 75 (21%) achieved BSA of 1%, 76 (21%) achieved BSA of 2% to 3%, and 154 (43%) maintained BSA >3%. Patients in the BSA >3% group at the 12-month visit had a worsening of DLQI by 46%, whereas patients who achieved BSA of 0% had a 71% improvement in DLQI score. Among the subsets of patients whose BSA improved but remained greater than 3% at 6 (n = 104) and 12 months (n = 86), there was a mean (standard error) decrease of 8% (13%) and increase of 4% (12%) in DLQI, respectively. We observed a significant association between BSA achievement and relative improvements in DLQI at 6 and 12 months (1-way analysis of variance, P < .001 for both) such that patients achieving lower BSA levels had higher mean DLQI improvement. Overall, 26% of patients achieved DLQI of 1 or less at 6 months and 43% of patients achieved DLQI of 1 or less at 12 months. The proportion of patients who achieved DLQI of 1 or less was highest among patients who had the lowest BSA at 6 and 12 months (chi-square test, P < .001 for both) (Fig 2).Fig 2Proportion of patients achieving DLQI 0/1 among patients with BSA of greater than 3% and DLQI of greater than 5 at enrollment (n = 167). Samples sizes for BSA achievement groups of 0%, 1%, 2% to 3% and greater than 3% at the 6- and 12-month visits are 22, 21, 34, and 90 and 26, 38, 37, and 66, respectively. (Chi-square test, P < .001 for both). BSA, Body surface area; DLQI, Dermatology Life Quality Index.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Our study shows that among patients with psoriasis being treated with systemic therapies, greater skin clearance indicated by BSA is associated with greater improvements in QoL. The results of our study further strengthen the evidence supporting the utility of BSA as an indicator of improvement in patient QoL. Editing and administrative support were provided by Carrie Bray of JK Associates, Inc, a member of the Fishawack Group of Companies, Conshohocken, PA, and were funded by AbbVie Inc, North Chicago, IL. Michelle D. Karpman, Corrona LLC, provided scientific writing support.