A review of the vitiligo literature to standardize the expression of disease severity

Abstract

Abstract The literature on vitiligo is extremely heterogeneous with limited standardization in vitiligo disease severity reporting. The IDEOM Vitiligo Workgroup initiated a project to develop an improved understanding of clinical reporting of vitiligo severity and extent. A medical librarian-developed literature review identified 51 English-language clinical trials treating vitiligo topically using topical corticosteroids or topical tacrolimus that included adult and paediatric patients, with 10 or more patients. Grading of studies was performed using SORT criteria. The grading systems used included three studies reporting overall improvement: one as absolute Improvement vs. did not improve (B2), one as marked improvement (C3) and one as improvement, no change or worse (A2). Severity was reported as straight body surface area scoring (BSA) in five trials with grades of (A1, A1, B1, C2 and C3), and two via photography and mapping (A1, A2). Many studies report success as meeting the metric of 50% improvement or clearance (C3). Kanwar et al. further subdivides this into 50% to <75% or >75% (C3). Three studies add the complete clearance metric (A1, A1, B1), with some adding worsening categories. Most studies create a grading system including G0- no change (A1, A1, A2, A2< B2, B2, B3, B3), G1- 1–25%, G2- 26–50%, G3- 51–75%, G4- 75–99% (one study by Lepe et al. reports this as >75%) and G5- 100% re-pigmentation [Bae et al. (C2) report these numbers as 0, 1–24%, 25–49%, 50–74%, 75–99%, 100%]. Variations in response include the meta-analysis by Lee et al. reporting >25%, >50% and >75% re-pigmentation and the combination of G0 and G1 as < or = 25% re-pigmentation, considered a failure (A1, A1, A2. B2, C3, C3, C3). Koopmans-VanDorp (B2) and Kandil (B2) break down re-pigmentation as none, beginning (<25%), good (25–90%) or complete or almost complete (90–100%) or spontaneous re-pigmentation. Success can be defined as G3–G5 or G4–G5. Kathuria classifies <50% as failure (A1). Hu and Farajzadeh (A2) classify >50% as success, Bae (C2) classifies >75% and Kumari (B2) as >90% improvement. Majid further subdivides the score into six subdivisions (A1). Abd-Elazim (A2) reports VASI and Baldo reports DLQI. Sach (C1) and Batchelor (A1) use the vitiligo noticeability scale Baldo, with target patches reported as ‘a lot less noticeable’ or ‘no longer noticeable’ being successful. Ibrahim (A2) uses Patient-Expressed Satisfaction, reporting ‘not satisfied’, ‘slightly satisfied’, ‘satisfied’ or ‘very satisfied’. Batchelor (A1) report percentage re-pigmentation, onset and maintenance of response, treatment burden, QoL, side effects and cost-effectiveness. Body surface area total and quartiles of improvement are the most commonly reported metrics in studies with high-level evidence. The addition of categories of no improvement, complete clearance, spontaneous improvement and worsening appears to enhance information collection. Collection of data using photographs or computer-assisted BSA monitoring enhances data reproducibility. Using 50%, 75% and 90% as thresholds for success appears to be standardized, with a rarer inclusion of 100%. Validated scores like VASI represent a validated alternative collection method, which can be modified to address the 50%, 75% and 90% thresholds. Quality of life has not per se been correlated to clinical response to topical therapeutics, and current scores including patient expression of satisfaction, vitiligo noticeability and satisfaction are not known to reflect topical response at this time.