A Classification Scale for Alopecia Areata: It’s Time to Incorporate the Patient Experience

October 13th, 2021

This is a Perspectives Blog post by a guest contributor to highlight progress in the treatment community. This perspective features a collaborative effort to create a more accurate scale to classify the severity of alopecia areata. Concert Pharmaceuticals was pleased to participate in this effort and welcomes this insight on the project from Dr. King.

By Brett King, MD, PhD
Associate Professor of Dermatology, Yale School of Medicine




Alopecia areata is an autoimmune disease with myriad presentations and effects:

  • It has an unpredictable course, coming and going for some and being chronic for others.
  • What hair-bearing site on the body will be affected at any moment in time is unpredictable.
  • It affects more than hair, and the eyes and nose can be affected, as well as fingernails and/or toenails.
  • It affects patients in a wide range of ways, often causing anxiety and depression and negatively impacting relationships and other aspects of life.

I’ve witnessed all of these things over and over again with my patients. Yet the clinical terms doctors have to classify the types of alopecia areata are largely based on a narrow description of patchy or complete scalp hair loss – that is, alopecia areata vs alopecia totalis (or universalis). Considering that there is even disagreement among experts about the meaning of alopecia totalis and alopecia universalis, you can see that our classification of the disease is sorely in need of revision in order to capture the diverse presentations and effects of alopecia areata.

Together with fellow dermatologist Maryanne Senna, MD, from Massachusetts General Hospital, we led the charge to change the conventional approach to the classification of alopecia areata. We believe it’s time to look at a broader picture of alopecia areata to classify the condition with greater detail and accuracy that reflects each patient’s overall clinical condition.

A new publication in the Journal of the American Academy of Dermatology (JAAD) highlights the result of our efforts: an academic-industry collaborative effort to develop a new alopecia areata disease severity scale for use in clinical practice.

The new severity scale, called the AA scale (Alopecia Areata Scale) is not just based on the amount of hair loss but it also captures additional key features of the disease and features that are important to patients.

Alopecia Areata Scale (AA scale)


Extent of scalp hair loss

Mild AA 20% or less scalp hair loss
Moderate AA 21-49% scalp hair loss
Severe AA 50-100% scalp hair loss

If mild or moderate, increase AA severity rating by 1 level if 1 or more of the following is present:

  • Negative impact on psychosocial functioning resulting from AA
  • Noticeable involvement of eyebrows or eyelashes
  • Inadequate response after at least 6 months of treatment
  • Diffuse (multifocal) positive hair pull test consistent with rapidly progressive AA

With the AA scale, physicians will have a simple tool to assess and classify alopecia areata.

I’m proud to be one of the authors of this JAAD publication, and I’m so appreciative of the collaborative efforts of the working group that developed the new classification scale, organized by Eli Lilly and Company. The working group included more than 20 clinicians and alopecia areata experts, including participants from leading academic institutions and biopharma companies developing new treatments for alopecia areata, including Concert Pharmaceuticals.

In this exciting time of advancement of our understanding of alopecia areata, which has led to promising treatments, we need better patient assessment tools. The AA scale will fill that role and marks another step forward in the journey toward effective treatment for those suffering from alopecia areata.



Dr. Brett King is Associate Professor of Dermatology at Yale University School of Medicine and specializes in alopecia areata. He is an investigator in numerous clinical trials, lectures nationally and internationally and publishes extensively. Dr. King received his B.A. at the University of California at Santa Cruz, his Ph.D. from Stanford University and his M.D. from Yale University School of Medicine. He completed medical internship at Massachusetts General Hospital and dermatology residency at Yale University School of Medicine.



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