Allergic reactions to insect bites and stings

Itching, redness, and a raised lump around the bite reflect inflammation at the site. A larger local reaction can spread beyond the immediate puncture area, whereas anaphylaxis produces symptoms away from the bite and may affect breathing or circulation.

A local reaction stays centred on the affected skin and may feel itchy, warm, or sore. Widespread hives, swelling of the lips or tongue, wheezing, vomiting, dizziness, or collapse indicate a body-wide response rather than an ordinary bite-site reaction. Scratching can break the skin and allow infection. Once inflammation settles, some skin tones develop a flat dark mark called post-inflammatory hyperpigmentation; this is pigment change rather than ongoing allergy.

Move away from the insect and wash the area gently with soap and water. If a visible stinger remains, scrape it sideways with a firm edge instead of squeezing the venom sac. A cool compress and elevation can reduce discomfort and swelling. Avoid scratching, and keep fingernails short. A pharmacist or clinician may recommend an oral antihistamine for itch or a topical corticosteroid for inflammation after checking suitability, skin location, and whether the surface is broken.

Use prescribed adrenaline at once and call emergency services if breathing becomes difficult, the tongue or throat swells, the voice changes, or the person becomes faint, confused, or collapses. Do not have the person stand or walk while awaiting help. Seek prompt assessment for a sting inside the mouth or near the eye, rapidly increasing swelling, severe pain, fever, pus, red streaking, or redness that continues to expand after the initial reaction.

After a body-wide reaction, ask whether specialist allergy assessment, prescribed adrenaline, and a written action plan are appropriate. Confirm how to store and use an auto-injector, which skin treatment is safe for bites, and what signs suggest infection rather than allergy. Mention the insect if known, the timing of symptoms, and any treatment already used.