Insect bites and stings

Last reviewed: 25 Aug 2022
Last updated: 27 Apr 2021

Summary

Definition

History and exam

Key diagnostic factors

  • witnessed bite/sting
  • local edema
  • local pain
  • local warmth
  • local markings
  • pruritus
  • wheal and flare
  • skin pallor
  • clamminess
  • signs of airway compromise
  • oropharyngeal edema
  • dyspnea
  • rales/crackles/wheeze
  • tachycardia
  • irregular pulse
  • skin flushing
  • altered alertness
More key diagnostic factors

Other diagnostic factors

  • pustules
  • bulls-eye-shaped rash
  • rash on palms and soles
  • linear raised rash
  • hypertension
  • fever
  • muscle cramp
  • diaphoresis
  • tremor
  • paresthesia and/or fasciculations
  • generalized pain
  • nausea/vomiting
  • headache
  • abdominal pain
  • history of immunocompromised state
  • history of cardiovascular disease
  • abscess
  • necrosis
  • cough
  • hypotension
  • arthralgia
  • adenopathy
Other diagnostic factors

Risk factors

  • occupational or recreational exposure to insects
  • geographic exposure to insects
  • previous history of anaphylactic (or anaphylactoid) response
More risk factors

Diagnostic investigations

1st investigations to order

  • clinical diagnosis
More 1st investigations to order

Investigations to consider

  • CBC
  • serum tryptase
  • sensitivity testing
More investigations to consider

Treatment algorithm

INITIAL

anaphylaxis/anaphylactoid reaction

ACUTE

local reaction

ONGOING

secondary infection: immunocompetent; low MRSA risk

Contributors

Authors

Tom Morrissey, MD, PhD
Tom Morrissey

Associate Professor

Department of Emergency Medicine

University of Florida

Jacksonville

FL

Disclosures

TM declares that he has no competing interests.

Acknowledgements

Tom Morrissey would like to gratefully acknowledge the assistance of Richard Vetter (MS) from the Department of Urban Entomology at the University of California.

Disclosures

Not disclosed.

Peer reviewers

Theodore M. Freeman, MD

Allergist and Immunologist

Jacobs Ramirez and Freeman Allergy & Immunology

San Antonio

TX

Disclosures

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

Andrew Parfitt, MBBS, FFAEM

Clinical Director

Acute Medicine

Associate Medical Director

Consultant Emergency Medicine

Guy's and St Thomas' NHS Foundation Trust

Clinical Lead and Consultant

Accident Emergency Medicine

St Thomas' Hospital

London

UK

Disclosures

AP declares that he has no competing interests.

Richard DeShazo, MD

Chairman and Professor

Department of Medicine

Professor of Pediatrics

Billy S. Guyton Distinguished Professor

University of Mississippi Medical Center

Jackson

MS

Disclosures

RD is an author of a reference cited in this topic.

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