Bites and stings
Most bites and stings are caused by insects, such as wasps and bees. They often cause pain and swelling but will usually not lead to any complications. However, some people may have an allergic reaction to a bite or sting, and it can even become life-threatening.
- Usually cause pain and mild swelling
- Many bites and stings have distinct characteristics
- Treatment is not usually necessary
If you are worried about a possible allergic reaction to a bite or sting, you can book an appointment to speak to one of our UK registered doctors online using our video consultation service. They can let you know about possible treatment and advice if you require it.
Insect bites rarely cause an allergic reaction, but some people may have itchy lumps or moderate swelling.
Allergic reactions to bites and stings can be categorised as either localised or general. Localised reactions will usually only require taking an antihistamine, whereas general allergic reactions are more serious and may require hospital admission.
What types of bites and stings are there?
Wasp, bee and hornet stings
They cause a sudden pain, followed by a red mark on the skin which usually lasts a few hours before resolving itself. During this period it could become swollen, and the itchiness can linger into the next day. Minor allergic reactions may occur where the sting lasts longer than a few hours. Bee stings cause similar symptoms but can be more painful, and the stinger will be left in the skin. All three stings may lead to anaphylaxis in rare cases, and this will require urgent medical attention.
Mosquito, midge, flea and gnat bites
Mosquito bites usually cause small red lumps on the skin, which are very itchy. They may also sometimes lead to fluid-filled blisters. In the UK, mosquito bites do not cause any harm, but they can in some parts of the world by spreading diseases such as malaria. Midge and gnat bites are similar to mosquito bites but smaller and more widespread.
Tick bites are harder to notice as they do not cause pain or itchiness immediately. They produce a very small red lump on the skin and can also lead to swelling, itchiness and blistering. Rarely, ticks in the UK carry Lyme disease, which produces a ‘bull’s eye’ rash.
Bites from spiders are very uncommon in the UK, but some which are native to the UK can leave a painful bite, such as the false widow spider. They usually leave characteristic puncture marks that are often painful and result in swelling. In rare cases in the UK, spider venom can cause nausea and vomiting.
Mite and bedbug bites
Bedbugs often do not cause any symptoms, but may cause itchy red lumps on repeat bites. Mite bites cause itchy red lumps on the skin. In some cases they can burrow underneath, leading to a condition called scabies.
What symptoms do different stings and bites cause?
Most bites and stings will cause small red lumps on the skin, which may be painful and itchy, depending on which insect has caused it. In the majority of cases the symptoms of a bite or sting will pass within a few hours and will not require any treatment.
Bites and stings will generally cause papules or wheals on the skin. A papule will be red and slightly raised from the skin and is often itchy. It is common for some inflammation to surround the sting or bite. A wheal is a larger, circular, raised mark on the skin which can be itchy but it is also temporary.
It is possible for an insect bite or sting to cause an infection, particularly if the mark is scratched as it leaves the area prone to bacteria entering. A tenderness around the bite or sting and the production of pus may be symptoms.
Allergies to insect stings and bites are uncommon; in the UK the most common allergic reaction is to a wasp sting. Wasp and bee sting venom is different and it is possible to become desensitised to a bee sting if you have previously had an allergic reaction. Anaphylaxis is the most severe reaction to a sting or bite and will require urgent medical attention.
How are stings and bites diagnosed?
To diagnose a bite or sting, a doctor will firstly want to find out whether the reaction is severe and life-threatening or less serious. If a doctor thinks that the reaction is non-allergic then they will not proceed with any testing, but they may decide to refer you to an allergy clinic if a generalised reaction has occurred.
Allergy clinics can conduct some tests to find out what type of venom you are allergic to. From this, they can then supply you with some emergency medication, in the form of a preloaded syringe of adrenaline, or you can be given small injections of the venom to desensitise the immune system. The second option takes several weeks to work and has a risk attached as a severe reaction could still take place.
What treatments are there for insect stings and bites?
In most cases, treatment is not necessary for insect stings and bites, but if you develop a mild or severe reaction you might need to ease the symptoms if the reaction is localised, or seek urgent medical attention.
If the site of your bite or sting is inflamed, swelling or particularly painful, there are several measures you can take to help. They include:
- Taking an antihistamine tablet as soon as possible, which will block the effect of the histamine; this is the chemical released when an allergic reaction occurs, causing the symptoms
- Taking a painkiller if you are struggling to cope with the pain
- Using a cold flannel to reduce the swelling
- Seeing a doctor about a possible course of corticosteroids if the inflammation does not go down after a few days
Severe reactions of insect stings or bites are uncommon but can be life-threatening. Wasp stings are the most likely to cause a serious allergic reaction. Anaphylaxis is treated initially with an adrenaline loaded pen to stop the body’s initial response to a sting or bite. This is then followed by oxygen to help you breathe. These procedures will take place whilst the person is being taken to hospital. Steroid injections may be administered at hospital, and possibly a fluid drip, if the reaction is particularly serious.
For tick bites, there are specific measures which need to be taken. The tick should be removed as soon as possible from the skin, preferably with tweezers. Best practice is to pull it out gently, as close to the skin as possible so that none of it remains in the skin. The site of the bite should then be cleaned with a disinfectant.
Talking to a doctor about stings and bites online
If you have developed a reaction to a sting or a bite and would like some advice about managing it, our doctors may be able to help. By booking an appointment through our online video doctor service you can consult with one of our GMC-registered doctors at a time that’s convenient for you.