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Last reviewed: 16 Mar 2025
Last updated: 27 Sep 2022

Summary

Definition

History and exam

Key diagnostic factors

  • pearly papule with a central dell

Other diagnostic factors

  • surrounding erythema
  • facial or groin distribution of lesions
  • pruritus
  • atopic dermatitis
  • sleep disturbance

Risk factors

  • close contact with an infected individual
  • sexual contact with an infected individual
  • atopic dermatitis
  • immunocompromise
  • tropical climate
  • swimming

Diagnostic tests

Tests to consider

  • dermoscopy
  • curettage biopsy
  • hematoxylin and eosin staining
  • full sexual health screen including HIV test

Treatment algorithm

Contributors

Authors

Nicholas Francis, PhD, MD, BA, MRCGP

Professor of Primary Care Research

Primary Care Research Centre

School of Primary Care, Population Sciences and Medical Education

University of Southampton

Southampton

UK

Disclosures

NF declares that he has no competing interests.

Acknowledgements

Dr Nicholas Francis would like to gratefully acknowledge Dr Nanette B. Silverberg, a previous contributor to this topic.

Disclosures

NBS declares that she has no competing interests.

Peer reviewers

David M. Ozog, MD

Director of Cosmetic Dermatology

Department of Dermatology

Cosmetic and Procedural Dermatology

Henry Ford Health System

Detroit

MI

Disclosures

DMO declares that he has no competing interests.

Anthony Ormerod, MB, ChB, MRCP, FRCP(Edin), MD, FRCP(Lond)

Consultant Dermatologist

Aberdeen Royal Infirmary

Aberdeen

UK

Disclosures

None disclosed.

Andrea Bershow, MD

Staff Dermatologist

VA Medical Center

Minneapolis

MN

Disclosures

AB declares that she has no competing interests.

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