What is it?
Most insect bites and stings are not serious and will get better within a few hours or days.
But occasionally they can become infected, cause a severe allergic reaction (anaphylaxis) or spread serious illnesses such as Lyme disease and malaria.
Bugs that bite or sting include wasps, hornets, bees, horseflies, ticks, mosquitoes, fleas, bedbugs, spiders and midges.
What are the symptoms?
An insect bite or sting often causes a small lump to develop, which is usually very itchy.
A small hole, or the sting itself, may also be visible. The lump may have an inflamed (red and swollen) area around it that may be filled with fluid. This is called a weal.
Insect bites and stings usually clear up within several hours and can be safely treated at home.
The symptoms that can occur from different types of insect bites are described below.
Midges, mosquitoes and gnats
Bites from midges, mosquitoes and gnats often cause small papules (lumps) to form on your skin that are usually very itchy. If youre particularly sensitive to insect bites, you may develop:
bullae fluid-filled blisters weals circular, fluid-filled areas surrounding the bite
Mosquito bites in certain areas of tropical countries can cause malaria.
Flea bites can be grouped in lines or clusters. If youre particularly sensitive to flea bites, they can lead to a condition called papular urticaria, where a number of itchy red lumps form. Bullae may also develop.
Fleas from cats and dogs can often bite below the knee, commonly around the ankles. You may also get flea bites on your forearms if youve been stroking or holding your pet.
A bite from a horsefly can be very painful. As well as the formation of a weal around the bite, you may also experience:
- urticaria a rash of weals (also called hives, welts or nettle rash)
- angioedema itchy, pale pink or red swellings that often occur around the eyes and lips for short periods of time
Horseflies cut the skin when they bite, rather than piercing it, so horsefly bites can take a long time to heal and can cause an infection.
Bites from bedbugs arent usually painful, and if youve not been bitten by bedbugs before, you may not have any symptoms.
If you have been bitten before, you may develop intensely irritating weals or lumps.
Bedbug bites often occur on your:
The Blandford fly
The Blandford fly (sometimes called blackfly) is usually found near rivers. Its common in:
- East Anglia
However, there have also been reports of Blandford fly bites occurring in other areas of England.
Youre most at risk of being bitten by a Blandford fly in May and June. Bites often occur on the legs and are very painful.
They can produce a severe localised reaction (a reaction confined to the area of the bite) with symptoms such as:
- a high temperature of 38C (100.4F) or over
- joint pain
Tick bites arent usually painful and sometimes only cause a red lump to develop where you were bitten. However, in some cases they may cause:
Ticks can carry a bacterial infection called Borrelia burgdorferi, which causes Lyme disease. Lyme disease can be serious if it isnt treated.
Mites cause very itchy lumps to develop on the skin and can also cause blisters. If the mites are from pets, you may be bitten on your abdomen (tummy) and thighs if your pet has been sitting on your lap. Otherwise, mites will bite any uncovered skin.
Spider bites from spiders native to the UK are rare. Youre more likely to be bitten by a spider while youre abroad, if you keep non-native spiders as pets, or if you have a job that involves handling goods from overseas.
Spider bites leave small puncture marks on the skin, which can be painful and cause redness and swelling.
In severe cases, a spider bite may cause nausea, vomiting, sweating and dizziness. Very rarely, a spider bite may cause a severe allergic reaction.
Wasps and hornets
A wasp or hornet sting causes a sharp pain in the area thats been stung, which usually lasts just a few seconds.
A swollen red mark will often then form on your skin, which can be itchy and painful.
A bee sting feels similar to a wasp sting, but the sting and a venomous sac will be left in the wound. You should remove this immediately by scraping it out using something with a hard edge, such as a bank card.
Dont pinch the sting out with your fingers or tweezers because you may spread the venom.
Most people wont have severe symptoms after being bitten or stung by an insect, but some people can react badly to them because theyve developed antibodies to the venom.
Youre more likely to have an allergic reaction if youre stung by an insect. The reaction can be classed as:
- a minor localised reaction this is normal and doesnt require allergy testing, although the affected area will often be painful for a few days
- a large localised reaction (LLR) this can cause other symptoms, such as swelling, itching and a rash
- a systemic reaction (SR) this often requires immediate medical attention because it can cause a potentially life-threatening allergic reaction (anaphylaxis)
Although insect bites and stings are a common cause of anaphylaxis, its rare to experience anaphylaxis after an insect sting, and its rarely fatal.
Large localised reactions and systemic reactions are described in more detail below.
###Large localised reaction (LLR)
If you have a large localised reaction (LLR) after being bitten or stung by an insect, a large area around the bite or sting will swell up. The area may measure up to 30cm (12in) across, or your entire arm or leg would swell up.
The swelling will usually last longer than 48 hours, but should start to go down after a few days. This can be painful, but the swelling wont be dangerous unless it affects your airways.
If youre bitten or stung many times by one or more insects, your symptoms will be more severe because a larger amount of venom will have been injected.
You may have an LLR several hours after being bitten or stung. This could include:
- a rash
- painful or swollen joints
###Systemic reaction (SR)
Youre more likely to have a systemic reaction (SR) if youve been bitten or stung before and become sensitised, particularly if it was recently. People whove been sensitised to bee stings are more likely to have an SR than people who are stung by wasps.
Dial 000 immediately to request an ambulance if youve been bitten or stung and have any of the following symptoms:
- wheezing, hoarseness or difficulty breathing
- nausea, vomiting or diarrhoea
- a fast heart rate
- dizziness or feeling faint
- difficulty swallowing (dysphagia)
- a swollen face or mouth
- confusion, anxiety or agitation
Its rare for an SR to be fatal, particularly in children, although someone with an existing heart or breathing problem is at an increased risk.
- Remove the sting, tick or hairs if still in the skin.
- Wash the affected area with soap and water.
- Apply a cold compress (such as a flannel or cloth cooled with cold water) or an ice pack to any swelling for at least 10 minutes.
- Raise or elevate the affected area if possible, as this can help reduce swelling.
- Apply aloe vera, apple cider vinegar, basil, black pepper, holy basil, mango, radishes, tamanu oil, or tea tree oil.
- Camphor oil is a very effective local anaesthesia as it causes numbness of the sensory nerves at the area of application.
- Avoid itching the affected area so it does not spread, as some can carry bacteria, parasites and viruses and a blood test is required to determine what this infection is.
Things to watch out for
Insect bites can be easily treated at home. GP should be contacted if symptoms dont start to improve within a few days or area around the bite becomes enlarged, red and swollen