A new scale to measure alopecia areata in treatment trials

Alopecia areata (AA) is a condition that causes individuals to lose hair on areas that may include the scalp, eyebrows, eyelashes, face, and body. It affects approximately 2% of the world's population. This USA‐based study had three aims: 1) to understand the most important concern of AA to patients; 2) to develop an investigator global assessment (IGA) scale that defines meaningful levels of scalp hair loss severity; 3) to determine treatment success (i.e. the amount of scalp hair required) for patients with at least 50% scalp hair loss. The study researchers interviewed 10 dermatologists and 30 patients with AA. The researchers learned that scalp hair loss was dermatologists’ key concern when treating patients; this was also the most bothersome aspect of AA for most patients. Using the interviewees’ descriptions of the key levels of AA scalp hair loss, the study researchers developed the Alopecia Areata Investigator's Global Assessment™ (AA‐IGA™). The AA‐IGA™ has five levels of scalp hair loss for use in AA treatment studies. The authors recommend that clinicians first use the Severity of Alopecia Tool (SALT) to assess the extent of scalp hair loss (0–100%) and then apply the AA‐IGA™ to interpret the amount of scalp hair loss that reflects dermatologists’ and patients’ perspectives and treatment goals. Nearly all dermatologists said that treatment that resulted in patients having 75–90% (median 80%) of their scalp hair would be successful. Similarly, patients reported that, short of 100%, they considered 70–90% (median 80%) scalp hair a treatment success. Linked Article: Wyrwich et al. Br J Dermatol 2020; 183 :702–709.