Clinicians rely on clinical measures to define the severity of atopic dermatitis and assess outcomes of therapy. These measures can be objective (ie, physician assessments of disease severity) or subjective (ie, patient-reported symptoms and quality of life outcomes). In this review, the most commonly used tools for assessing atopic dermatitis severity in adult patients are presented and compared. These include Eczema Area and Severity Index (EASI); SCORing Atopic Dermatitis (SCORAD); Physician Global Assessment (PGA); body surface area (BSA); Atopic Dermatitis Severity Index (ADSI); Six Area, Six Sign Atopic Dermatitis (SASSAD); Patient Oriented Eczema Measure (POEM); Dermatology Life Quality Index (DLQI); and pruritus Numerical Rating Scale (NRS). Available severity strata for the tools are summarized, although the use of severity strata in clinical practice is not recommended. Since both objective and subjective assessments of disease severity are important to assess, consideration of clinical characteristics such as disease recurrence or persistence, as well as location of the affected areas, should be considered in the overall judgement of disease severity and consideration of therapy choice.

Many AD patients respond satisfactorily to topical or systemic treatments, but for those patients who do not respond or have contraindications, new biologic agents appear to be promising therapies.

Introduction: An estimated 2-4% of Western populations are thought to have psoriasis, with a regional incidence ranging from 0.09% to 11.43%. Variance in estimates is a result of differences in study populations, methodology, regional differences, and definitions of disease. Reliable prevalence estimates of plaque psoriasis are challenging to establish. Further, the distribution of psoriasis severity in the population is unknown. This study aims to establish the utility of expert elicitation (EE) as a method for estimating unknown parameters in dermatology by (1) estimating the prevalence of psoriasis in the adult population, and (2) estimating previously unknown disease severity distribution. Methods: An expert panel of 11 Canadian dermatologists with demonstrated expertise in psoriasis was formed. A proof-of-concept EE exercise estimated psoriasis prevalence in the general population in Canada, followed by estimation of psoriasis disease severity distribution by body surface area (BSA). Expert estimates were consolidated using Bayesian methods to statistically model the data and represent uncertainty. Results: The median prevalence of psoriasis in the adult population using the Bayesian estimate was 3.0% (95% credibility interval, 2.7-3.3%), compared with the estimated mean prevalence of 3.4% (95% confidence interval, 2.2-4.9%). By EE, the estimated cumulative distribution of disease severity assessed by BSA suggests that approximately 50% of patients have a BSA of \ 3% and 78% of patients have a BSA of \ 10%, with only 2% having a BSA of [ 50%. Conclusion:The EE approach resulted in prevalence estimates that had a narrow distribution and were consistent with published literature, supporting its value in dermatology as a complementary method to help guide decisionmaking in areas where evidence is scarce or uncertain.