Most people expect a mosquito bite to be a minor irritation – a small, itchy bump that disappears within a day or two. But for some, the body’s response can be far more intense: severe swelling, redness, and pain.
This condition is known as Skeeter Syndrome, a local allergic reaction to proteins in mosquito saliva.
Though often mistaken for an infection or other skin condition, Skeeter Syndrome is a relatively common but underrecognized immune response. Understanding the symptoms, causes and treatment is key – especially for parents (because children are at higher risk of having Skeeter Syndrome), individuals with a history of allergies, and anyone living in mosquito-prone areas.
Skeeter Syndrome vs. Typical Mosquito Bites: What’s the Difference?
A typical mosquito bite will show a small, raised bump that will fade quickly without treatment.
Skeeter Syndrome, on the other hand, is accompanied by a much larger, more painful, and inflamed area that can extend several inches beyond the bite.
A Skeeter Syndrome bite can turn into blisters that can last for up to one week.
The discomfort level with Skeeter Syndrome can be moderate to severe and may interfere with daily activities.
“The area of swelling can be more than two to three inches,” said
“The area of swelling can be more than two to three inches,” said Elise Liu, MD, an allergist and immunologist at Yale School of Medicine. “The severe reaction will kick in within a few hours and it can eventually become very swollen, red, and hot to the touch.”
The Immune Response Behind Skeeter Syndrome
When the mosquito bites, it injects a small amount of saliva into the skin. This saliva contains proteins that prevent blood from clotting and allow the mosquito to feed more easily.
For those with Skeeter Syndrome, the body treats those proteins as a serious threat.
In other words, Skeeter Syndrome is an allergy to mosquito bites. Like other types of allergies, Skeeter Syndrome is caused by allergic antibodies, called immunoglobulin E (IgE).
After a mosquito bite, allergy cells called mast cells will release a chemical like histamine, which causes redness, swelling, warmth and itching. In Skeeter Syndrome, these reactions are amplified.
“Some people have immunoglobin E (IgE) antibodies against mosquito protein, which leads allergy cells called mast cells to become activated when they encounter mosquito saliva protein,” explained Dr. Liu. “Unlike other types of allergies like food allergies, mosquito bite allergies do not tend to be life threatening. For example, in someone who has a peanut allergy, when they eat peanuts, it can be absorbed into the bloodstream and cause a body wide reaction can be life threatening. In mosquito bite allergy, the salivary proteins tend to just stay in the skin, so the reaction happens primarily in the skin. Body wide allergic reactions to mosquito bites are extremely rare.”
Does Skeeter Syndrome Run in Families?
Children are at higher risk of having Skeeter Syndrome. Sometimes, these allergic reactions can get smaller with time, as people can become desensitized to the mosquito allergen with repeated bites.
People with a family history of allergies – such as asthma, eczema, hay fever or food allergies are more likely to experience exaggerated immune responses to mosquito bites.
This is because the tendency to have allergic conditions can run in families.
Individuals with a tendency to develop allergic conditions also have a higher risk of developing Skeeter Syndrome. This includes:
- Personal history of other allergic conditions
- Family members with known allergic reactions
- Personal history of strong reactions to insect bites or stings
Effective Treatment Options for Skeeter Syndrome
Prevention is the best medicine. Using strategies to avoid mosquito bites is the best way to prevent the discomfort of Skeeter Syndrome. These tips include limiting activities at dawn and dusk, avoiding wetland areas where there are a lot of mosquitoes, and using DEET-containing insect repellant when outdoors.
If a mosquito bite happens, Skeeter Syndrome can often be managed effectively with over-the-counter treatments.
Oral antihistamines such as Zyrtec, Claritin or Allegra are commonly used to relieve itching, redness, and swelling caused by the allergic reaction.
These antihistamine medications help block the histamine released by allergy cells during the body’s immune response to mosquito saliva and can be especially helpful if symptoms affect multiple areas or are interfering with sleep.
Topical corticosteroids, like hydrocortisone cream, are another first-line treatment.
“You can get prescription strength topical steroids or even one percent hydrocortisone over the counter. If your reaction is severe or affecting a sensitive area, such as the eye, oral steroids can also be an option,” added Dr. Liu.
For immediate relief, applying a cold compress or ice pack to the affected area can minimize swelling and soothe discomfort.
Regardless of treatment, it is important to avoid scratching the bites, as this can increase the risk of developing an overlying infection. Individuals should seek medical attention if symptoms are limiting their activities, last more than a few days without improvement, worsen, or show signs of infection such as pus, or fever.
Learn more about Allergy and Immunology services at Yale New Haven Hospital.
