Health

Insect bites and stings

On September 4, 2019 by

Symptoms of an insect bite or sting

When an insect bites, it releases saliva that can cause the skin around the bite to become red, swollen, and itchy. Often, the venom from a bite also causes an inflamed, itchy red mark (wheal) to form on the skin. This can be painful, but in most cases it is harmless. The affected area will usually remain somewhat painful and itchy for a few days.

The severity of the stings and bites varies depending on the type of insect and the sensitivity of the person.

In rare cases, some people may have a severe allergic reaction (anaphylaxis) to a bite or sting, which requires immediate medical treatment.

More information on the symptoms of insect bites and stings is available here.

Should I consult a doctor?

See your doctor if there is a lot of swelling or blistering, or if there is pus, which is an indication of infection.

Call an ambulance immediately if you have any of the following symptoms:

  • wheezing or difficulty breathing
  • nausea, vomiting, or diarrhea
  • a fast heart rate
  • dizziness or feeling faint
  • swallowing difficulties (dysphagia)
  • confusion, anxiety or agitation

More information on the complications of insect bites and stings is available here.

Treatment of insect bites and stings

The treatment for most bites and stings is as follows

  • wash the affected area with soap and water
  • place a cold compress (a mitten or cloth soaked in cold water) over the affected area to reduce swelling

Try not to scratch the affected area to avoid infection. If you are in pain or the area is swollen, take pain relievers, such as acetaminophen or ibuprofen.

For a more serious reaction, your doctor may prescribe another medication or refer you to an allergy clinic for immunotherapy.

More information on treating insect bites and stings is available here.

Prevention of insect bites and stings

You are more exposed to a sting or bite if you work outdoors or regularly participate in outdoor activities, such as camping or hiking.

Using insect repellent and keeping your skin covered will help prevent a bite or sting.

Try not to panic if you find a wasp, hornet, or bee nest and back away slowly (do not move your arms or hit them).

More information on preventing insect bites and stings is available here.

Travelling abroad

There is a risk of contracting diseases from insect bites, such as malaria, when travelling to other parts of the world, such as:

  • Africa
  • Asia
  • South America

It is important to be aware of any risks that may arise prior to travel and to obtain any medications or vaccinations that may be necessary for such travel.

Symptoms

Often, an insect bite or sting causes a small lump to appear, which usually bites a lot.

A small cavity or the sting itself is also visible. The bump may have an inflamed area (red and swollen) around it that may be filled with fluid. This is called a wheal.

Insect bites and stings usually disappear after several hours and can be safely treated at home.

Types of insect bites

The symptoms that can occur differ depending on the types of insect bites listed below.

Flies and mosquitoes

Flies and mosquito bites often cause the formation of small papules (bumps) on the skin that usually bite a lot. If you are particularly sensitive to insect bites, you may develop the following:

  • flicthenae (fluid-filled blisters)
  • beans (fluid-filled circular areas surrounding the bite)

Mosquito bites in certain areas of tropical countries can transmit malaria.

Fleas

Flea bites can be grouped in lines or clusters. If you are especially sensitive to flea bites, a condition called papular urticaria (in which several red bumps form) may occur. Blisters may also occur.

Cat and dog fleas usually bite below the knee, but also around the ankles. They can also affect the forearms if you have been petting or holding your pet.

Horseflies

A bite from a horsefly can be very painful. In addition to the formation of a blister around the sting, you may experience

  • hives: a blistering rash (also called wheal or irritation)
  • dizziness
  • Weakness
  • sibilance
  • Angioedema — itchy, pale pink or red swelling that often occurs 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 cause infection.