Summary
Definition
Alopecia areata (AA) is an autoimmune disease that affects almost 2% of the population in the US.[1] Inflammatory cells target the hair follicle, thus preventing hair growth. Typically, a small round patch of hair is noticed.
[Figure caption and citation for the preceding image starts]: Alopecia areataProvided by Paradi Mirmirani, MD [Citation ends]. This patchy hair loss may regrow spontaneously. In other cases there can be extensive patchy hair loss and in rare cases there is loss of all scalp and body hair (alopecia areata universalis).
History and exam
Key diagnostic factors
- hair loss
- non-scarring alopecia
- exclamation mark hairs
- positive hair-pull test
- normal underlying skin in bare areas
- nail pitting
Diagnostic investigations
Treatment algorithm
Contributors
Authors
Professor of Dermatology/Medicine (Retired)
David Geffen School of Medicine
UCLA
Los Angeles
CA
Disclosures
RAS is currently an honorary member of the National Alopecia Areata Foundation (NAAF) clinical scientific advisory board.
Dr Richard A. Strick would like to gratefully acknowledge Dr Jack Green and Dr Paradi Mirmirani, previous contributors to this monograph. JG is an author of a reference cited in this monograph. PM declares that he has no competing interests.
Peer reviewers
Professor and Chair
Department of Dermatology
University of Minnesota
Minneapolis
MN
Disclosures
MH declares that she has no competing interests.
Associate Professor
Department of Dermatology
University Hospital of Zurich
Zurich
Switzerland
Disclosures
RMT is an author of a number of references cited in this monograph.
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