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While the health information and fact sheets on this website relate to world-wide situations, the drug names will vary between countries – therefore the advice of your local GP should be sought.
Insect bites and stings
Published by Bupa's health information team, July 2009.
This factsheet is for people who would like information on how to prevent and treat insect bites and stings.
In the UK, insect bites and stings are usually no more than a nuisance, causing a few red, itchy spots or lumps. However, in some people they can cause severe allergic reactions, so it's important to know what to do if this happens.
In countries affected by malaria and other diseases spread by insects, trying not to get bitten is one of the most important parts of staying healthy.
About bites and stings
The following insects that are found in the UK can bite or sting.
- Common biting insects include bedbugs, flies, fleas, midges, mites, mosquitoes and ticks.
- Common stinging insects include bumblebees, honeybees, hornets and wasps.
When an insect or other small creature bites you, they make a tiny hole in your skin, often to get to the blood that they feed on. Stings contain chemicals that are very irritant to the skin and can trigger allergic reactions.
Symptoms of bites and stings
Bites from insects that feed on your blood, for example mosquitoes, often result in itchy spots or lumps. These don't usually need any treatment and clear up within a day or so. The same generally applies for insect stings.
Sometimes bites and stings can lead to complications such as skin infections or an allergic reaction. Rarely, a bite or sting can cause a dangerous allergic reaction, called anaphylaxis, so it's important to know what to do if this happens. The symptoms of anaphylaxis are described later in this factsheet.
If you notice you're getting bitten around your ankles or feet at home, it may be the result of cat or dog fleas.
Complications
Infection
Insect bites or stings can get infected with bacteria. Instead of clearing up after a few days, the bite gets redder and more sore, and pus may build up inside. Infected bites may make you feel unwell, with flu-like symptoms and swollen glands.
Allergic reaction
This happens if you're allergic to the insect's saliva (for a bite) or venom (for a sting). These allergic reactions are usually around the area of the bite or sting. This is called a localised reaction and may take a few days to clear up.
Your immune system protects your body from infection. An allergic reaction happens when your immune system mistakes a harmless substance for a harmful one and triggers an immune response. This involves the release of natural chemicals such as histamine that cause symptoms such as itching and swelling. The substance responsible for causing the allergic reaction is called an allergen. For example, if you're allergic to insect bites or stings, the allergen will be the saliva from the bite or the venom from the sting.
To get an allergic reaction, your body needs to have been exposed to an allergen before. This is called sensitisation.
Anaphylaxis
Anyone who develops a serious allergic reaction needs urgent medical attention. This serious allergic reaction is called anaphylaxis or anaphylactic shock. A person having a reaction will have some or all of these symptoms:
- red, blotchy skin
- swelling of the lips, eyes, face or neck
- difficulty in breathing
- rapid pulse
- itchiness all over
- a rash
- fainting
- severe anxiety
- vomiting and diarrhoea
If you have had a serious allergic reaction before, it's wise to wear a medical identification bracelet or tag. This gives details of your allergy and a telephone number that anyone can call for more information in case you develop anaphylaxis. Your GP may also prescribe a dose of adrenaline to carry with you. Single doses of adrenaline are available in the form of an EpiPen or AnaPen. This consists of a sterile syringe of adrenaline that is ready to be used in an emergency.
Adrenaline should be given if severe symptoms develop within minutes. In a serious reaction, the affected person will often have difficulty breathing and signs of low blood pressure such as fainting, paleness, clammy skin and a fast heart beat.
Treatment for bites and stings
Urgent medical attention is needed for anyone who:
- shows signs of having a severe allergic reaction (anaphylaxis)
- has been stung by several insects at the same time
- has been stung in the mouth or throat, where the swelling can interfere with breathing
Self-help
Insect bites can be painful or itchy, but try not to scratch them as this can make the symptoms worse. Wash the affected area with soap and water and pat the skin dry.
You can relieve the pain by applying a cold compress (a cloth soaked in iced water).
Stings are typically painful and cause swelling of the skin, but aren't usually dangerous unless you're severely allergic to the venom. If a sting is still visible in the wound, remove it as soon as possible. You can scrape it out with a fingernail or a credit card. Don't try to grab the sting between your fingers or tweezers as this can cause the venom sac to squeeze its contents into your skin.
Medicines
You may wish to use a local anaesthetic spray to reduce pain. A cream or ointment containing hydrocortisone can help reduce swelling and inflammation. You can buy low-dose hydrocortisone cream over the counter but don't use it on children under 10, or on your face or on broken or infected skin. You may also wish to try an antihistamine cream or soothing cream such as calamine lotion. Over-the-counter painkillers such as paracetamol can relieve some of the discomfort.
If the lump or itchiness spreads beyond the original site of the bite, antihistamine tablets can relieve the symptoms. Some antihistamines may cause drowsiness. This can be an advantage at night when the itchiness might interfere with sleep, but it can be dangerous if you need to drive or operate machinery.
If you have an infected bite or sting, your GP may prescribe antibiotics as a lotion or cream to apply to the affected area. For a more severe infection, such as one that's giving you a fever, you may need a course of antibiotics to take by mouth.
Always ask your doctor or pharmacist for advice and read the patient information leaflet that comes with your medicine.
Tick bites
Ticks are tiny spider-like creatures (not in fact insects at all) that attach to the skin and feed on blood. They usually feed on animals such as sheep and horses. If you find a tick attached to your skin, remove it as soon as possible with tweezers by grasping as close as possible to the skin so you don't leave the head or mouth parts behind.
In some areas, particularly where there are wild deer, ticks may carry a bacterial infection (the bacterium is called Borrelia burgdorferi) that can cause a condition called Lyme disease. If you develop flu-like symptoms or a rash within a few weeks of a tick bite, it's important that you see a doctor. Lyme disease can be treated with antibiotics. If left untreated, it can cause more serious symptoms affecting the nervous system, joints and heart.
Prevention of bites and stings
You can reduce your risk of insect bites and stings by:
- wearing insect repellent
- sleeping under a suitable net if mosquitoes are a problem at night
- wearing long sleeves and trousers if out in the evening, especially near water - tucking trousers into socks or boots, and shirts into trousers will also help
- keeping picnic foods covered up as much as possible - sweet foods and drinks attract wasps
Bites and stings abroad
In the UK, the threat to health from animal bites and stings is relatively low. This isn't always the case abroad, and it's important for travellers to be aware of the hazards that exist in other countries they visit. Your GP can give you up-to-date advice about appropriate preventive treatments.
In tropical countries, malaria is one of the most important issues to consider. In malarial areas, take care not to get bitten by using an insect repellent containing the chemical diethyltoluamide (DEET) and covering up at the key biting times (usually dusk and dawn). A bed net impregnated with an insecticide is another important way of avoiding bites.
Related topics
Further information
Sources
- Insect bites - background information. Clinical Knowledge Summaries. www.cks.library.nhs.uk, accessed 7 March 2009
- Simon C, Everitt H, Kendrick T. Oxford handbook of general practice. 2nd ed. Oxford: Oxford University Press, 2006
- Insect bites and stings - management. Clinical Knowledge Summaries. www.cks.library.nhs.uk, accessed 7 March 2009
- Lanacane cream. Lanacane. www.lanacane.co.uk, accessed 28 February 2009
- Benzocaine. electronic Medicines Compendium. www.emc.medicines.org.uk, accessed 28 February 2009
- Joint Formulary Committee, British National Formulary. 57th ed. London: British Medical Association and Royal Pharmaceutical Society of Great Britain. 2009
- Emergency treatment of anaphylactic reactions. Guidelines for healthcare providers. Resuscitation Council (UK), www.resus.org.uk, January 2008
- How to remove a tick. Lyme Disease Action. www.lymediseaseaction.org.uk, accessed 7 March 2009
- Lyme borreliosis / Lyme disease. Health Protection Agency. www.hpa.org.uk, accessed 7 March 2009
- Lalloo DL, Hill DR. Preventing malaria in travellers. BMJ 2008; 336(7657):1362-6 www.bmj.com
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
Publication date: July 2009