When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Insect bites and stings

Last reviewed: 30 Sep 2024
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
Full details

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
Full details

Risk factors

  • occupational or recreational exposure to insects
  • geographic exposure to insects
  • previous history of anaphylactic (or anaphylactoid) response
Full details

Diagnostic tests

1st tests to order

  • clinical diagnosis
Full details

Tests to consider

  • CBC
  • serum tryptase
  • sensitivity testing
Full details

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.

  • Insect bites and stings images
  • Differentials

    • Cellulitis
    • Periorbital and orbital cellulitis
    • Abscess
    More Differentials
  • Guidelines

    • Anaphylaxis - a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis
    • Anaphylaxis - a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis
    More Guidelines
  • Patient information

    Insect bites and stings

    More Patient information
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer