Wow! All this wonderful moisture in southern Colorado has made a wonderful environment for our gardens, our trees and our insects. Don’t let the bug bites get you down. To help, we’ve put together information about allergic reactions to insect bites.
First, let’s put this in perspective. While insect bites and stings are fairly common being truly allergic to an insect is quite rare. The most common insect bites we experience are from mosquitos, but other bugs can bite as well like horse and deer flies. One of my favorites is the kissing bug or triatoma which is common in the southwest Unites States. This is different from insect stings common among hymenoptera like wasp, yellow jacket and hornets as well as bees and imported fire ants.
When your favorite board-certified allergist says ‘allergy’ he may mean something different than what your grandma intended when she said, ‘allergy.’ When I am talking about allergy I mean to detail a reaction that is mediated by a specific branch of the immune system, specifically, Immunoglobulin E, AKA, IgE. Immunoglobulin E is the molecule that ‘remembers’ an allergy. You can have specific IgE for foods, pollens and even insects. This can be evaluated with either the allergy skin test or sometimes with a blood test. A life-threatening allergic reaction to insect bites is quite rare.
Allergic Reactions to Insect Bites

It is common to have reactions to insect bites, especially mosquitos, and especially at this time of year with all this moisture. Remember: when it comes to mosquitos that it’s the females who do all the damage. The males are perfectly content sipping on water and nectar. However, the females hone in on a combination of factors: elevated carbon dioxide in the breath and certain scents as well as sweat. For uncertain reasons they seem to prefer men, those with type O blood, and people who are overweight. When the female finds you she inserts the proboscis and drinks your blood. It has been estimated that they need 6 seconds or more of contact to elicit a reaction. A reaction may not appear for up to 48 hours after the bite.
The most common reaction, an itchy red bump, is the result of an immune system reaction to the mosquito’s saliva. Adults generally have smaller reactions because after being bit multiple times they become less sensitive to the bites.
Besides an itchy bump one may experience other types of reactions:
- Large lesions
- Bruises
- Lymphangitis (swelling of the lymph system around the bite)
- Hives (around the bite)
- Anaphylaxis (multi-system allergic reaction that can be life-threatening)
Don’t forget that many other disease may be transmitted by insect bite:
- West Nile Virus (this has been documented in North America)
- Malaria
- Dengue fever
- Encephalitis
- Yellow Fever
- Meningitis
Signs that a reaction to an insect bite may be something more severe:
- Fever
- Confusion
- Neck pain
- Severe Headache
- Body aches
- Light sensitivity
- Confusion
- Rash
- Nausea or Vomiting
- Neurological changes (like weakness on one side of the body)
If any of these symptoms occur then report to a physician or health care provider quickly.
Prevention:
Investigate your house for standing water. Think of pots, puddles, upside down toys, tires and anywhere that water is left standing. These are the places that mosquitos love to hang out.
Other Preventative Measures:
- Dusk and dawn are the most popular time of day for mosquitos.
- Wear light colored clothing, including pants and socks. Consider fully covering the body.
- Use citronella scented candles in outdoor areas.
- Use mosquito repellant with 6 to 25 percent DEET.
Treatment:
- Prevention is worth a lot more than the treatments.
- It is imperative that you keep the area clean and dry. Insect bites commonly become infected skin lesions due to scratching and not keeping the area clean.
- For itching try oral antihistamines like Benadryl, Zyrtec or Claritin.
- Topical solutions like anti-itch creams or lotions containing benzocaine may help.
- Make a paste with 50/50 Benadryl cream and steroid cream (like cortisone) and apply it several times per day.
- A cool bath without soap may help.
- If there is a concern about severe allergic reactions then be sure to get injectable epinephrine like an Epi-pen and keep it available.
If you have questions or concerns about your insect bites and the risk of severe reactions then please contact us at Asthma & Allergy Associates.
Recently edited. Originally published June 10, 2015.