These Horrifying Symptoms Could Signal a Severe Mosquito Bite Allergy

Photo credit: dimid_86 - Getty Images
Photo credit: dimid_86 - Getty Images

From Prevention

There’s nothing worse than coming home from a hike, camping trip, or barbecue and discovering a ton of itchy, painful mosquito bites speckling your skin. Even worse: Your friend or sibling who was with you the entire time has no bites at all. So, what gives?

Well, it helps to know how and why a mosquito bites you in the first place. Only females are out for blood, explains Joseph M. Conlon, an expert with The American Mosquito Control Association who worked as an entomologist for 25 years.

“Female mosquitoes imbibe blood as a protein source for egg development,” Conlon says. When the female mosquito “bites” you, she inserts the tip of her mouth into one of your blood vessels, injecting her saliva into your bloodstream. The saliva contains a protein that prevents your blood from clotting as she eats. (What a pleasant thought, right?)

It’s these proteins, not the bite itself, that cause the swelling, redness, and itching that some-but not all-of us experience. It’s true: Seeing no reaction after a bite could mean you’re one of the lucky few who aren’t allergic to mosquito saliva, says Andrew Murphy, MD, a fellow at the American Academy of Allergy, Asthma & Immunology.

It also could mean you’ve developed an immunity to mosquito bites. “When a person has had repeated exposure to the mosquito allergen, her immune system can stop recognizing the allergen as a problem, and there is no reaction,” Dr. Murphy says.

However, many of us do have some type of allergy to these pesky bug bites-ranging from common, minor bumps to rare, severe reactions. Here are the symptoms to keep an eye out for and what you can do to find relief.


Minor mosquito bite allergy: Small red bump

What it looks like: round, white-ish bump, often with a small visible dot at the center; becomes red and firm after 1 or 2 days

What it means: This is the most common mosquito bite allergy and the reaction is more annoying than anything, says Jorge Parada, MD, medical director of the Infection Control Program at Loyola University Chicago and medical advisor for the National Pest Management Association. “This minor allergic reaction is in response to proteins in the mosquito’s saliva.”


Moderate mosquito bite allergy: Welts

What it looks like: slightly raised, smooth, flat-topped bumps that are usually more reddish than the surrounding skin

What it means: Some people are more sensitive to the mosquito’s proteins, explains Dr. Parada. This sensitivity causes them to react with larger welts instead of the traditional small bump. “However, some studies have found that the reaction is also a function of the mosquito’s feeding time,” he adds. “The longer the mosquito feeds, the more mosquito proteins are released, thereby increasing the chance of a visible reaction.”


Serious mosquito bite allergy: Hives and fever (aka skeeter syndrome)

What it looks like: welts accompanied by skin swelling, heat, redness, and itching or pain, along with a fever

What it means: You may have a reaction known as skeeter syndrome, a more extreme mosquito bite allergy. It can lead to excessive swelling of the bite area, as well as feeling hot and hard to the touch. Sometimes the bite area can even blister and ooze. While anyone can develop skeeter syndrome (even those with no prior extreme reaction to mosquito bites), Dr. Murphy says young children, patients with immune system disorders, and travelers exposed to new types of mosquitoes are at a higher risk.


Severe mosquito bite allergy: Anaphylaxis

What it looks like: hives, lip/tongue swelling, trouble breathing, wheezing, coughing

What it means: While anaphylaxis from mosquito bites is rare, it can be fatal. “Patients with anaphylaxis to mosquitoes will have the typical symptoms of a severe allergic reaction,” Dr. Murphy says. He mentions hives, lip or tongue swelling, trouble breathing, wheezing, coughing, and-in severe cases-passing out or death. “Treatment is the use of injectable epinephrine and seeking immediate medical attention,” he adds.

🚨 If you suspect a mosquito bite is causing serious symptoms like fever, excessive swelling, hives, and swollen lymph nodes, seek emergency help.

How to treat and prevent mosquito bites

If you do fall on the minor to moderate end of the spectrum, there are a few things you can do at home to help get rid of mosquito bites faster.

First, swabbing the bite area with rubbing alcohol can help reduce your body’s histamine response (the chemical produced by your immune system that causes allergic reactions) by clearing away the mosquito’s saliva, according to Jonathan Day, PhD, a mosquito researcher and professor of medical entomology at the University of Florida.

Dabbing your skin with ice, calamine lotion, or 1 percent hydrocortisone cream can also help tame inflammation, relieve itching, and overall soothe the skin. If that’s not doing the trick, popping an oral antihistamine, like Benadryl, can also turn off your body’s histamine response to reduce swelling and itching.

More importantly, preventing mosquito bites in the first place should be your first priority. That way, you don’t have to worry about mosquito-borne diseases like Zika or West Nile viruses, or even chikungunya, malaria, and dengue fever if you’re traveling outside of the U.S.

Avoiding peak mosquito hours (dusk and dawn), investing in an outdoor fan to prevent them from flying near you, and applying insect repellent that contains ingredients like DEET, oil of lemon eucalyptus, IR3535, and picaridin can go a long way in keeping the bug bites at bay.

Additional reporting by Markham Heid


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