How Are Insect Allergies Diagnosed?
Reviewed by: HU Medical Review Board
If you think you might be allergic to insect stings, it is important to see an allergist for a diagnosis. An allergist can help determine whether your reaction is a typical reaction or an allergic reaction. A proper diagnosis will also help you manage your allergy and treat it if a sting does occur.1-3
Your doctor will use 3 methods to diagnose an insect sting allergy. Taken together, these tools help your doctor rule out or confirm that you are allergic to these insects. These steps include:1-3
- Taking a detailed medical history
- Conducting a physical exam
- Ordering various allergy tests
Medical history and physical exam
Your doctor will ask you many questions about your general health and the sting that led you to their office. Questions may include:
- What stung you?
- What were you doing when you were stung?
- Do you have a photo of the insect?
- Have you been stung before? How many times? What was your reaction? How long did the reaction last? What did you do to treat the sting?
- Do you know if you have any other allergies?
- Do you have any other health conditions?
- What medicines and supplements do you take?
The doctor will also conduct a physical exam. They will look at your skin, eyes, ears, and throat, and listen to your breathing. If the place where you were stung is still visible, they will want to look at it.
Then, they may order blood tests or skin tests.
Which insect was it?
Identifying the insect that stung you is important, if you can. Most insect stings in the United States come from wasps, yellow jackets, hornets, and honeybees. In the southern United States, fire ants can also be a major cause of insect stings.1
Yellow jackets build nests that look like paper-maché, either in the ground or in walls. Bees also build nests in the ground, in walls, and in trees. Hornets and wasps nest in bushes, trees, and on buildings. You may come into contact with them while gardening, eating, or playing outside.1
Fire ants build their nests on top of and under the ground. The mound often looks like a pile of dirt.1
Tests are not always ordered for insect sting allergies. However, your doctor may order a blood test, skin-prick test, or intradermal skin test.1
A skin prick test involves scratching a small amount of the allergen on your skin and allowing it to seep in. After about 15 minutes, the doctor or nurse will check for any redness, swelling, or itching. Sometimes, a hive-like bump (wheal) will appear. Usually, the larger the wheal, the more likely it is you are allergic to the substance.1
The size of a wheal does not predict how severe your reaction will be the next time you are stung.1
If the skin-prick test is negative or inconclusive, your doctor may order an intradermal skin test. This involves injecting a small amount of venom just under the skin. It works the same way as a tuberculosis test. After a certain amount of time (usually 15 minutes), the area is checked for any reactions. This test is thought to be more accurate than other tests for insect sting allergies.1
Finally, if both these tests are negative, your doctor may order blood tests.1
If all testing is negative, the tests may be repeated at 3 and 6 months to see if the earlier tests missed the small number of people who are actually allergic.2