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Leaflet: Insect Bites and Stings


What may happen after an insect sting or bite?

A small local skin reaction: Most people will be familiar with the common local skin reactions caused by insects.
An insect sting: typically causes an intense, burning pain. This is quickly followed by a patch of redness and a small area of swelling (up to 1 cm) around the sting. This usually eases and goes within a few hours.
An insect bite: you may not notice the bite (although some can be quite painful, particularly from a horsefly). However, saliva from the insect can cause a skin reaction such as:
Irritation and itch over the site of the bite.
A small itchy lump (papule) which may develop up to 24 hours after a bite. This typically lasts for several days before fading away. Sometimes some redness (inflammation) surrounds each papule.
A weal which is like a small fluid-filled lump and is very itchy. It may develop immediately after being bitten. A weal lasts about two hours, but is often followed by a small itchy solid lump which develops up to 24 hours later. This can last for several days before fading away. Occasionally, small skin reactions following an insect bite persist for weeks or months.

A localised allergic skin reaction

Some people have an allergic reaction to the venom in a sting. A localised reaction causes swelling at the site of the sting. This becomes larger over several hours, and then gradually goes away over a few days. The size of the swelling can vary, but can become many centimetres across. The swelling may even extend up an entire arm or leg. The swelling is not dangerous unless it affects your airway. However,  if it is severe, the skin may break out in blisters.

Skin infection

Occasionally, a skin infection develops following a bite, particularly if you scratch a lot, which can damage the skin and allow bacteria (germs) to get in. Infection causes redness and tenderness around the bite. Over a period of several days, this may spread and, sometimes, can become serious.

Do I need antibiotics?

The vast majority of insect Bites or stings do not require antibiotics. The redness, swelling and itching are part of the normal response to a bite or sting.

Antibiotics are only required if you:

Feel unwell and have a high temperature

The Fluid filled centre looks like thick yellow custard, rather than the normal reaction of cider coloured clear fluid

There is a red line tracking from the main area of swelling and redness.

What is the treatment for an insect sting or bite?

If stung by a bee and the stinger is still in place – scrape it out.

Scrape out a bee sting left in the skin as quickly as possible. Use the edge of a knife, the edge of a credit card, a fingernail, or anything similar.

The quicker you remove the sting the better, so use anything suitable to scrape out the sting quickly.

Do not try to grab the sting to pluck it out, as this may squeeze more venom into the skin. Scraping it out is better.

Note: Wasps, hornets or yellow jackets do not leave a stinger in the skin when they sting.

Take an antihistamine tablet as soon as possible. You can buy these at pharmacies.

Use a cold compress to ease pain and to help reduce swelling. For example, use a cold flannel or an ice pack.

Painkillers such as paracetamol or ibuprofen can help to ease the pain.

A steroid cream may be useful – for example, hydrocortisone.

Continue with antihistamines until the swelling eases. This may be for a few days. See a doctor if the swelling is severe.

Visit the Minor Injuries Unit webpage for more information about this service.

Date of creation: April 2019
Date of review: April 2021
URN: 104