What Are the Symptoms of Insect Allergies?

Most people have a mild reaction to being stung by a hornet or fire ant. Mild pain, redness, and swelling are normal reactions to the insect’s venom.1

The stinging insects that most often cause humans problems come from the Hymenoptera (hi-men-op-tu-rah) family. This group includes:1

  • Honeybees
  • Paper wasps
  • Yellow jackets
  • Yellow hornets, white-faced hornets
  • Fire ants

Most people have at least a mild reaction to being stung by a bee or wasp. However, some people have a serious allergy to the venom of stinging insects.1

Reactions to insect stings

The most common symptoms of an insect sting are:1

  • Pain when stung, and sometimes for a few hours after
  • Redness and swelling where you were stung

Mild reactions tend to develop within minutes and go away in a few hours. The spot will be 1 to 2 inches in size. Some people may have a bump for 1 to 2 days. This is called an uncomplicated reaction.1,2

Symptoms of a stronger reaction are more noticeable and last longer. Large local reactions occur in 1 out of every 10 people with insect sting allergies. With a large reaction, the bump will be about 4 inches across and more swollen and red than a mild reaction. The bump will slowly get bigger over 1 to 2 days and last 5 to 10 days.1,2

The most serious reaction is called a systemic reaction, which is more rare. Some people react with hives in addition to a large bump. For others, the whole body reacts, often within minutes. This is known as anaphylaxis. Symptoms involve more than 1 organ system, such as the skin, lungs, heart, and gut. Examples include:3,4

  • Mouth – Itching, swelling of the lips and tongue
  • Throat – Itching, swelling in throat, throat closing, hoarseness
  • Skin – Itching, hives, redness, swelling, flushing
  • Gut – Vomiting, diarrhea, cramping
  • Lungs – Shortness of breath, wheezing, coughing
  • Heart – Weak and rapid pulse, dizziness, fainting, pale or blue skin
  • Other – Feeling something bad is about to happen, confusion

Anaphylaxis may be life-threatening if left untreated. In fact, insect stings are a leading cause of death due to anaphylaxis.1,2

Adults tend to have more severe reactions and more deaths resulting from those severe reactions.1

Symptoms of biting insect allergies

People also have allergic reactions to other types of insects. Biting insects usually cause minor pain, redness, and itching around the bite. These bites rarely lead to a severe reaction. Biting insects include:2

  • Mosquitoes
  • Kissing bugs
  • Bedbugs
  • Fleas
  • Certain flies

Symptoms of household pests

Household pests like dust mites and cockroaches cause different allergy symptoms than biting or stinging insects. Household pests cause:2,5

  • Runny nose
  • Sneezing
  • Itchy nose, eyes, ears, and mouth
  • Nasal congestion
  • Red or watery eyes
  • Swelling around the eyes
  • Coughing
  • Wheezing
  • Shortness of breath

People sensitive to these insects react to the insect waste instead of a sting or bite. Dust mites and cockroaches are some of the most common causes of year-round allergy and asthma symptoms.2

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Written by: Jessica Johns Pool │ Last reviewed: March 2022