Table of ContentsView AllTable of ContentsBite AppearanceOther SymptomsWhen to See a ProviderHome TreatmentWays to Prevent Bites
Table of ContentsView All
View All
Table of Contents
Bite Appearance
Other Symptoms
When to See a Provider
Home Treatment
Ways to Prevent Bites
Black flies are small insects closely related to mosquitoes that bite and suck the blood of livestock and humans. The bites can be painful and long-lasting.
Black flies are also called “buffalo gnats,” because they have a small hump behind their head, similar to a bison or buffalo.They usually hatch near flowing water in late spring and early summer and can swarm in large numbers. They are found in most of the United States but are more common in the upper Midwest and Northeast.
What Do Black Fly Bites Look Like?
Ablack fly bitelooks like a mosquito bite, appearing as a small bump on the skin that may be inflamed. You may be able to see the hole where it punctured your skin to feed on blood.
Only the females bite.You may not feel it initially because the flies inject a numbing substance into your skin. Black flies often attack your head or face but can bite you anywhere.
The bites can become painful and itchy and may swell or lead to blisters. The symptoms are a reaction to the insect’s saliva, which contains toxins and substances that prevent your blood from clotting quickly so the insect can feed.
Other Common Symptoms
Sometimes, black fly bites can cause what’s known as “black fly fever,” though technically, the insects do not infect humans with diseases. Still, symptoms can include:
Black fly bite symptoms can last for many days.
Late complications of black fly bites include persistent eruptions that can last from three to 16 months. These can show various types of skin disorders, including erythematous (red or discolored) and edematous (swelling) reactions, persisting for weeks or months.
When to Contact a Healthcare Provider
It’s not common, but some people may have asevere allergic reactionto black fly bites due to the substances the flies inject into the skin. In very rare cases, many bites at one time could be life-threatening.
If you seesigns of infection, such as increased pain, redness or discoloration, warmth, or pus, that’s also a sign to contact a healthcare provider.
A Word From VerywellIn rare cases, black fly bites can cause extreme hypersensitivity reactions. This may include severe cellulitis, and in rare instances, complications such as Guillain-Barré syndrome and nephrotic syndrome. Remember that prevention is a million times better than cure, so the best strategy is to avoid getting bitten.—KASHIF J. PIRACHA, MD, MEDICAL EXPERT BOARD
A Word From Verywell
In rare cases, black fly bites can cause extreme hypersensitivity reactions. This may include severe cellulitis, and in rare instances, complications such as Guillain-Barré syndrome and nephrotic syndrome. Remember that prevention is a million times better than cure, so the best strategy is to avoid getting bitten.—KASHIF J. PIRACHA, MD, MEDICAL EXPERT BOARD
In rare cases, black fly bites can cause extreme hypersensitivity reactions. This may include severe cellulitis, and in rare instances, complications such as Guillain-Barré syndrome and nephrotic syndrome. Remember that prevention is a million times better than cure, so the best strategy is to avoid getting bitten.
—KASHIF J. PIRACHA, MD, MEDICAL EXPERT BOARD
How to Find Relief at Home
If you see black fly bites on your skin, you can take thefollowing steps to treat them:
It’s hard to repel black flies because they can appear in such large numbers. They may fly around your head, into your eyes or ears, or get in your hair. However, you can take steps you can take to avoid bites, including:
Summary
Black flies are small insects with a big bite. They hatch near flowing water in late spring and early summer in the U.S. Midwest and Northeast and can appear in swarms.
To prevent the bites, which can be painful and last a long time, avoid areas where they are hatching or wear long-sleeved shirts and long pants, plus a hat. Consider using insect repellent, though the insects will fly around your eyes, face, and hair. A head net may be useful in areas with swarms.
Treat bites with topical anti-itch and pain spray or a cold compress. Contact your healthcare provider if you feel faint or see signs of infection.
6 SourcesVerywell 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.University of Florida.Featured creatures.Purdue University.Black flies.Metropolitan Mosquito Control District.Biting gnat/black fly control.National Park Service.What’s biting you?Illinois Department of Public Health.Prevention and control, biting flies.American Academy of Dermatology Association.Tips to prevent and treat bug bites.
6 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.University of Florida.Featured creatures.Purdue University.Black flies.Metropolitan Mosquito Control District.Biting gnat/black fly control.National Park Service.What’s biting you?Illinois Department of Public Health.Prevention and control, biting flies.American Academy of Dermatology Association.Tips to prevent and treat bug bites.
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.
University of Florida.Featured creatures.Purdue University.Black flies.Metropolitan Mosquito Control District.Biting gnat/black fly control.National Park Service.What’s biting you?Illinois Department of Public Health.Prevention and control, biting flies.American Academy of Dermatology Association.Tips to prevent and treat bug bites.
University of Florida.Featured creatures.
Purdue University.Black flies.
Metropolitan Mosquito Control District.Biting gnat/black fly control.
National Park Service.What’s biting you?
Illinois Department of Public Health.Prevention and control, biting flies.
American Academy of Dermatology Association.Tips to prevent and treat bug bites.
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