Last reviewed: 4 Feb 2021
Last updated: 11 Jun 2018
Summary
Definition
History and exam
Diagnostic investigations
Treatment algorithm
Contributors
Authors

Associate Professor of Pediatrics
Duke University School of Medicine
Durham
NC
Disclosures
MJS declares that he has no competing interests.
Dr Michael J. Smith would like to gratefully acknowledge Dr Theoklis Zaoutis, a previous contributor to this topic. TZ declares that he has no competing interests.
Peer reviewers
Associate Professor of Pediatrics and Family Medicine
Department of Pediatrics
Hasbro Children's Hospital
Providence
RI
Disclosures
RR declares that he has no competing interests.
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