Summary
Definition
The term 'insect' refers to a distinct taxonomic class. However, it is used generically throughout this topic to represent a multitude of bugs, including arachnids. Encounters with insects or arachnids can result in bites or stings.
Bites stem from puncture with a proboscis (animal head appendage) or fangs, or from chewing with mouth parts. Depending on the source, bites range from being immediately painful to completely unfelt, and health consequences may be caused by local trauma, the injection of various substances (irritants, venoms, poisons, toxins, anaesthetics, enzymes, anticoagulants), disease transmission, secondary infection, or systemic allergic reactions (rare).
Stings from insects are administered from ovipositors (animal organs used for laying eggs that may also inject various noxious substances) or modified ovipositors (e.g., barbed stingers of bees and wasps). Stings are almost always immediately painful. Reactions range from local irritation and swelling to life-threatening anaphylactic reactions.
[Figure caption and citation for the preceding image starts]:
Honeybee stinging flesh
Courtesy of Rick Vetter
[Citation ends].
[Figure caption and citation for the preceding image starts]:
Close-up of honeybee stinger
Courtesy of Rick Vetter
[Citation ends].
History and exam
Key diagnostic factors
- presence of risk factors
- witnessed bite/sting
- local oedema
- local pain
- local warmth
- local markings
- pruritus
- wheal and flare
- skin pallor
- clamminess
- signs of airway compromise
- oropharyngeal oedema
- dyspnoea
- rales/crackles/wheeze
- tachycardia
- irregular pulse
- skin flushing
- altered alertness
Other diagnostic factors
- pustules
- bullseye-shaped rash
- rash on palms and soles
- linear raised rash
- hypertension
- fever
- muscle cramp
- diaphoresis
- tremor
- paraesthesia and/or fasciculations
- generalised pain
- nausea/vomiting
- headache
- abdominal pain
- history of immunocompromised state
- history of cardiovascular disease
- abscess
- necrosis
- cough
- hypotension
- arthralgia
- adenopathy
Risk factors
- occupational or recreational exposure to insects
- geographical exposure to insects
- previous history of anaphylactic (or anaphylactoid) response
Diagnostic investigations
Treatment algorithm
Contributors
Authors VIEW ALL
Associate Professor
Department of Emergency Medicine
University of Florida
Jacksonville
FL
Disclosures
TM declares that he has no competing interests.
Tom Morrissey would like to gratefully acknowledge the assistance of Richard Vetter (MS) from the Department of Urban Entomology at the University of California.
Peer reviewers VIEW ALL
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.
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.
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.
Use of this content is subject to our disclaimer