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Alopecia areata

Last reviewed: 28 Oct 2023
Last updated: 23 Sep 2022



History and exam

Key diagnostic factors

  • hair loss
  • nonscarring alopecia
  • exclamation point hairs
  • normal underlying skin in bare areas
  • nail pitting
More key diagnostic factors

Other diagnostic factors

  • autoimmunity
Other diagnostic factors

Risk factors

  • autoimmune disease
  • family history of autoimmune disease
More risk factors

Diagnostic investigations

1st investigations to order

  • clinical diagnosis
  • positive hair pull test
More 1st investigations to order

Investigations to consider

  • skin biopsy
  • trichoscopy
More investigations to consider

Treatment algorithm


limited hair loss (treatment desired)

limited hair loss (no treatment desired)


extensive hair loss (treatment desired)

extensive hair loss (no treatment desired)



Fong Seng Lim, MBBS, MMed (FM), FAMS

Senior Consultant

Department of Family Medicine

National University Health System



FSL declares that he has no competing interests.

Miny Samuel, PhD

Assistant Director

Research Support Unit

Yong Loo Lin School of Medicine

National University of Singapore



MS declares that she has no competing interests.


Dr Fong Seng Lim and Dr Miny Samuel would like to gratefully acknowledge Dr Richard A. Strick, Dr Jack Green, and Dr Paradi Mirmirani, previous contributors to this topic. RAS is an honorary member of the National Alopecia Areata Foundation (NAAF) clinical scientific advisory board. JG is an author of a reference cited in this topic. PM declares that he has no competing interests.

Peer reviewers

Maria Hordinsky, MD

Professor and Chair

Department of Dermatology

University of Minnesota




MH declares that she has no competing interests.

Ralph M. Trueb, MD

Associate Professor

Department of Dermatology

University Hospital of Zurich




RMT is an author of a number of references cited in this topic.

  • Alopecia areata images
  • Differentials

    • Trichotillomania
    • Tinea capitis
    • Telogen effluvium
    More Differentials
  • Guidelines

    • British Association of Dermatologists' guidelines for the management of alopecia areata 2012
    • Alopecia areata investigational assessment guidelines: part II
    More Guidelines
  • Patient leaflets

    Alopecia areata

    More Patient leaflets
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