Anaphylaxis from a wasp sting: emergency response and follow-up

Pain, redness, and swelling at the sting site are local effects. Widespread hives, tongue or throat swelling, wheezing, breathing difficulty, vomiting with other allergic symptoms, dizziness, or collapse suggest a systemic reaction.

Anaphylaxis after a sting can progress quickly and does not require a rash. Swelling limited to the limb that was stung may be a large local reaction rather than anaphylaxis, although swelling near the mouth or neck deserves careful assessment because of its location.

Wasps can sting more than once and often leave no stinger behind. If a stinger is visible, remove it promptly without delaying treatment for any whole-body reaction.

Administer the prescribed epinephrine auto-injector into the outer thigh as soon as anaphylaxis is suspected, then call local emergency services. Follow the personal action plan if symptoms persist or return.

Have the person lie flat with legs raised. If breathing is hard, sitting with legs extended may help; if unconscious but breathing, use the recovery position. Do not let the person stand suddenly or walk to transport, and do not delay epinephrine while searching for a stinger.

Request emergency help for throat tightness, voice change, swelling inside the mouth, noisy breathing, wheezing, severe dizziness, confusion, fainting, or collapse. Widespread symptoms developing rapidly after a sting also justify emergency action.

Assessment in an emergency department is still needed after apparent recovery because symptoms may return. Seek urgent advice for a sting inside the mouth, around the eye, or for many stings, even if anaphylaxis is not yet evident.

Ask for referral to an allergy specialist and whether testing for wasp venom is appropriate. Discuss whether venom immunotherapy may be suitable, how to recognise the threshold for epinephrine, and how prescribed devices should be carried.

Request a written emergency plan for home, work, and travel. Practical prevention topics include covering sweet drinks outdoors, wearing footwear, moving calmly away from wasps, and arranging safe removal of nearby nests by trained pest-control services.