COVID-19: Click here for the latest updates and vaccine news

26th September, 20195 min read

Insect bites

Medically reviewed

All of Healthily's articles undergo medical safety checks to verify that the information is medically safe. View more details in our safety page, or read our editorial policy.


Insect bites are quite common and often cause a small, itchy lump to develop. They can become red and inflamed, and fluid sometimes develops in the area around the bite.

Insect bites can usually be treated at home, and should get better in a short period of time.

Different insect bites cause different symptoms.

Midges, mosquitoes and gnats

If you have been bitten by a midge, mosquito, or gnat then you will usually develop a small, itchy lump where you’ve been bitten.

Some people also develop fluid-filled blisters (bullae), or fluid-filled areas that develop circularly around the bite (weals).

In some tropical areas, mosquito bites can cause malaria.


Flea bites are small red bumps and they usually appear in clusters. They can be very itchy and sometimes itchy red lumps can appear. This is known as papular urticaria, or hives.

Often flea bites come from cats and dogs, so they are common around your ankles or your forearms after you’ve been stroking or carrying a cat or dog.


Horsefly bites tend to be more painful than other types of bites. They cause a circular, fluid-filled area to develop around the bite (weal).

They can sometimes cause hives, dizziness, weakness, wheezing, and itchy pink or red swellings around the lips and eyes (angioedema).

Since horseflies cut the skin when they bite, they can take more time to heal and also carry the risk of infection.


You can’t usually feel bedbug bites, and symptoms can take a few days to develop.

If it’s the first time you have been bitten by bedbugs then you may not have any symptoms, but if you have been bitten before you may experience itchy weals or bumps.

The Blandford fly

Blandford fly bites can cause more severe reactions than other bites.

If you have been bitten by a Blandford fly then you can develop swelling, blistering, a high temperature, and joint pain in the affected area.


Insect bites usually don’t cause severe reactions and they can be treated at home. But if your symptoms are severe, or you are worried about your bite, then you should see a doctor.

You can treat an insect bite by:

  • washing the area where you were bitten with soap and water
  • placing a cold flannel or cloth on the affected area to help reduce swelling
  • avoiding scratching the bite because this can lead to infection

If your reaction to the bite is more severe and you experience pain and swelling you can also:

  • place an ice pack (wrapped in a towel) on the bite
  • take painkillers — speak to a pharmacist or doctor on whether to take painkillers and how to get and use them
  • use a local anaesthetic, antihistamine or mild hydrocortisone (1%) cream or spray
  • take an antihistamine tablet — speak to a pharmacist or doctor for further guidance on whether to take antihistamines and how to get and use them

See a doctor if the swelling is severe, and seek immediate medical help if you experience a generalised allergic reaction.


It’s not always possible to prevent insect bites, but you can minimise your risk of being bitten by:

  • wearing long sleeves and long trousers
  • not wearing bright colours, or strong-smelling cosmetics which might attract insects
  • using an insect repellent
  • wearing a complete head covering - this is mainly used in areas where midges are common



One of the most common complications of an insect or bug bite is infection. Secondary bacterial infections can either occur when you are bitten or as the result of scratching a bite.

Secondary bacterial infections that happen as a result of an insect or bug bite include:

Complications from tick bites

Tick bites can sometimes transfer a bacterial infection at the time of the bite, which can lead to Lyme disease.

Learn more about the signs of Lyme disease and how to treat it.

Complications from mosquito bites

In Africa, Asia, Australia, and the Middle East, mosquito bites can spread West Nile virus.

Find out how to prevent being bitten, and the serious symptoms of West Nile virus.

Mosquitos can also spread malaria in certain tropical locations. If malaria is not treated properly it can be fatal, so it’s important to know how to prevent malaria if you are travelling to a tropical region.

Generalised allergic reaction

A small number of people will have a generalised allergic reaction after being bitten. This type of reaction needs to be treated immediately.

Symptoms of a generalised allergic reactions include:

  • itchy skin which is followed by an itchy, blotchy rash
  • facial swelling, including the lips, tongue, throat, and upper airway
  • a feeling of impending doom, anxiety, confusion or agitation
  • abdominal cramps
  • nausea
  • blood vessels dilating, which may cause: your skin to become red, your heart rate to increase, your blood pressure to drop (which may cause dizziness or fainting)
  • wheezing or difficulty in breathing
  • difficulty swallowing

Seek immediate medical help if you experience symptoms of a generalised allergic reaction.

When to worry

See a doctor if your bite looks infected, or you have a skin reaction that doesn’t go away and seems to be getting worse.

You should seek immediate medical help if you develop symptoms of a generalised allergic reaction. If you already have an EpiPen, use it immediately.

Visit insect bites and stings for more information.

Was this article helpful?

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.