Insect bites and stings

Reactions range from local irritation and mild swelling to gross oral swelling and difficulty in breathing.

Treatment is usually entirely supportive, aimed at alleviating immune reactions. Severe reactions and anaphylaxis require immediate intervention to maintain airway patency and prevent cardiovascular collapse. Injected adrenaline (epinephrine) is the mainstay treatment of severe reactions.

Fatal spider bites are exceedingly rare. Most spider bites can be treated with supportive care.

Guidelines are mainly based on clinical experience and expert consensus, owing to the variability and unpredictability of reactions.

There is a risk of late-phase (delayed) anaphylactic reactions.

Primary care physicians should be notified of severe reactions involving their patients.

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 fleshCourtesy of Rick Vetter [Citation ends].[Figure caption and citation for the preceding image starts]: Close-up of honeybee stingerCourtesy of Rick Vetter [Citation ends].