Insect bites and stings explained

What normally happens

When an insect bites or stings, it injects saliva or venom, and the body reacts with local inflammation. This typically causes a small red, swollen lump that itches or feels sore, sometimes with a tiny blister. Mosquito, midge, flea, and bedbug bites usually itch, while bee, wasp, and hornet stings tend to hurt sharply at first. For most people these reactions are unpleasant but harmless and fade over a few hours to a few days. Some people get a larger area of swelling around the site, which can look alarming but is still a local reaction rather than a dangerous allergy. Scratching makes itching worse and can break the skin, so it is best avoided. Knowing what is normal helps you judge when something needs more than simple self-care.

Soothing bites and stings at home

Most bites and stings can be managed at home. If a bee sting is still in the skin, brush or scrape it out sideways as soon as possible rather than squeezing it, which can release more venom. Wash the area with soap and water. A cold compress, such as a cloth-wrapped ice pack, held on for around ten minutes eases pain and swelling, and raising the affected limb can help reduce swelling too. Try not to scratch, and keep the area clean to lower the risk of infection. A community pharmacist can recommend treatments to relieve itching or swelling and advise on what is suitable for children or during pregnancy. Symptoms usually improve within a few days; keeping fingernails short can help stop scratching from breaking the skin.

Spotting an infected bite

Sometimes a bite or sting becomes infected, particularly if it has been scratched. Signs of infection tend to appear over the following days rather than straight away, and include increasing pain, spreading redness or warmth around the site, swelling that gets worse, pus or fluid leaking out, and swollen glands. A fever or feeling generally unwell can also point to infection. This is different from the immediate reaction, which is at its worst soon after the bite and then settles. If you think a bite has become infected, see a pharmacist or GP, as some infections need treatment. In the UK, certain bites, such as tick bites, can occasionally pass on infections like Lyme disease, so a spreading circular rash after a tick bite is worth getting checked promptly.

Recognising a severe allergic reaction

Very rarely, a sting or bite triggers anaphylaxis, a severe and rapidly developing allergic reaction that is a medical emergency. Warning signs include difficulty breathing or noisy, wheezy breathing; swelling of the face, lips, mouth, tongue, or throat; a tight throat or trouble swallowing; a widespread rash or hives; feeling faint, dizzy, or suddenly very unwell; and collapse or loss of consciousness. If any of these happen, phone 999 immediately and say you think it is anaphylaxis. If the person has an adrenaline auto-injector prescribed for allergies, it should be used straight away as they have been trained, and a second dose may be needed if there is no improvement. Lay the person down with their legs raised, or sit them up if breathing is hard, and stay with them until help arrives.

Preventing bites and when to get help

You can reduce bites by covering exposed skin, using insect repellent, and avoiding known problem areas at dusk when many insects are active. Check yourself and children for ticks after walking in grassy or wooded areas, and remove any ticks promptly with fine-tipped tweezers, pulling steadily upwards close to the skin. See a pharmacist or GP if a bite becomes infected, if swelling is severe or spreads, if you feel unwell, or if a bite is near the eye or in the mouth or throat. Anyone who has had a serious allergic reaction to a sting should seek specialist allergy advice and may be prescribed emergency medication. Above all, treat the emergency signs of anaphylaxis as a 999 call every time, without waiting to see if things improve.