Table of ContentsView AllTable of ContentsAppearanceIs It Dangerous?When Do They HappenHome CareSeeking Medical CarePrevention
Table of ContentsView All
View All
Table of Contents
Appearance
Is It Dangerous?
When Do They Happen
Home Care
Seeking Medical Care
Prevention
Horseflies come from theTabanidaefamily of insects, which also includes deerflies. These large, blood-sucking flies have strong mandibles that resemble scissors or blades and contain small “hooks" that cut into your skin. This makes horsefly bites surprisingly painful in comparison to many otherbug bites.
While horsefly bites are painful and itchy, they’re usually not dangerous. In rare cases, a person may have an allergic reaction and need immediate medical attention. This article explains what you can do about the bite and when you need to reach out to a healthcare provider.
David McGlynn / Getty Images
What Does a Horsefly Bite Look Like?
Horseflies are typically between one-half inch and a little over 1 inch long. They tend to have black or gray bodies, short antennae, large heads, and large green eyes.
Horsefly bites usually look like large, swollen welts around a central point. They tend to be red or discolored, irritated, and itchy. Female horseflies are aggressive and may bite more than once, so you may have multipleskin lesions.
Is a Horsefly Bite Dangerous?
Horsefly bites might seem scary because they can be so painful and itchy, but they typically aren’t dangerous. Your swelling and other symptoms should go down on their own after a few days.
In rare cases, horsefly bites can lead to the following health complications:
When Do Horsefly Bites Typically Happen?
Horseflies are drawn to heat and sunlight. This makes them more likely to bite in bright, sunlit areas during the hot summer months.
Horsefly bites are also especially common near bodies of water and in areas where there are manywild or domesticated animals. This is because they often bite other warm-blooded mammals, such as horses, cattle, and dogs, in addition to humans.
What You Can Do for a Horsefly Bite at Home
When to Contact a Healthcare Provider
Most horsefly bites can be resolved on their own at home. However, you should contact a healthcare provider if:
Your healthcare provider may prescribe additional treatments, such asantibioticsortopical corticosteroids, to relieve the above symptoms.
Call 911 or go to the hospital for emergency treatment if you have any signs of anaphylaxis (a severe allergic reaction) after a horsefly bite, such as:
How to Prevent Horsefly Bites
Summary
If your symptoms persist, or if you notice any symptoms of anaphylaxis, such aslight-headednessor severe swelling, reach out to a healthcare provider immediately.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Pestworld.org.Do horse flies really bite?
MedlinePlus.Insect bites and stings.
Kelly K, Grose P.Horsefly (genus Tabanus) bite: Allergy or infection?.BMJ Case Rep. 2023;16(2):e253641. doi:10.1136/bcr-2022-253641
MedlinePlus.Tularemia.
Buonomo A, Rizzi A, Aruanno A, Nucera E.Anaphylaxis after horsefly sting: A strange case of wasp-horsefly syndrome.Postepy Dermatol Alergol. 2021;38(2):331-332. doi:10.5114/ada.2021.106212
MedlinePlus.Insect bites and stings - bug bites.
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