Skeeter Syndrome

If a mosquito bites you and you then develop large areas of swelling eight to 10 hours later, you may have skeeter syndrome. Other symptoms include itching, fever and possibly blisters.


Skeeter syndrome, an allergic reaction to the saliva of the mosquito that bites you, creates a lump surrounded by swelling.
The large area of swelling on the arm of a child bitten by a mosquito is characteristic of skeeter syndrome.

What is skeeter syndrome?

Skeeter syndrome is a large local allergic reaction to mosquito bites marked by significant inflammation. If you have it, you’re allergic to substances in the mosquito’s saliva. Some people have so much swelling that they have trouble moving.


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Who does skeeter syndrome affect?

Although it’s relatively rare, skeeter syndrome can affect anyone. However, it often affects children, older adults and others who may have impaired or undeveloped immunity levels. Very young children who haven’t been able to develop an immunity to mosquito bites are the most likely people to develop skeeter syndrome.

You may have had typical reactions to mosquito bites all your life, but then suddenly develop an allergy to the saliva. One reason for this may be changes within your immune system. Another reason for the change may be that you’re highly allergic to the saliva of one type of mosquito but not to another.

How does skeeter syndrome affect my body?

With skeeter syndrome, people may develop fever as well as a large local allergic reaction.

Skeeter syndrome may be confused with cellulitis in some cases, especially when the bites happen to young children. Providers may prescribe antibiotics, but antibiotics won’t help skeeter syndrome. Cellulitis, an infection, can happen days after a bite when scratching results in infection.


Symptoms and Causes

What are the symptoms of skeeter syndrome?

Symptoms of skeeter syndrome may include:

  • Large areas of swelling.
  • Skin warmth.
  • Skin color or texture changes, such as reddening of lighter color skin or darkening or other appearance changes in darker color skin. This also may include the area getting harder.
  • Itching.
  • Pain.
  • Blisters.
  • Fever.

What causes skeeter syndrome?

Skeeter syndrome occurs as a result of an allergic reaction to proteins in mosquito saliva. A mosquito has a long mouthpart called a proboscis that it uses to bite you. The mosquito pierces your skin, sucks your blood and secretes saliva into your bloodstream. Being allergic to the polypeptides in the saliva of a biting mosquito causes skeeter syndrome.

If you’re allergic to these polypeptides, you may see skeeter syndrome symptoms starting about eight to 10 hours after the mosquito bites you. Symptoms typically resolve within three to 10 days.


Is skeeter syndrome contagious?

No. You can’t catch skeeter syndrome from anyone and you can’t give it to anyone.

Diagnosis and Tests

How is skeeter syndrome diagnosed?

Your healthcare provider will take a medical history and do a physical examination. They may ask you:

  • If you were bitten by mosquitoes.
  • If you’ve had previous reactions to mosquito bites.
  • If you’ve traveled to a different country or different part of the country. Different types of mosquitoes have different types of saliva.
  • About the timeline between when you were bitten and when the rash started.
  • If you have any other signs and symptoms that concern you, such as shortness of breath.

Management and Treatment

How is skeeter syndrome treated?

If your provider thinks you have a mild case of skeeter syndrome, they will suggest that you:

  • Take oral antihistamines.
  • Cover the bite with hydrocortisone cream.
  • Take over-the-counter pain relievers/fever reducers such as acetaminophen or ibuprofen if you have pain or fever, or both.

If you have a more severe case of skeeter syndrome, you may need to take systemic corticosteroids. Steroids are available as pills or injections.

How long will it take me to recover from skeeter syndrome?

You should probably recover from skeeter syndrome in three to 10 days.


How can I prevent skeeter syndrome?

The best way to prevent skeeter syndrome is to prevent mosquito bites. This means:

  • Eliminating any standing water.
  • Avoiding areas infested with mosquitoes.
  • Using a bug spray registered with the Environmental Protection Agency (typically containing DEET).
  • Wearing long pants and long sleeves. Wear thick clothes if you can because mosquitoes can bite through thin clothes.
  • Using screens to cover windows and doors.
  • Staying indoors when mosquitoes are most active (dusk and dawn).
  • Treating your clothing, tents and nets with mosquito repellants.
  • Covering your sleeping area with protective nets.

If you have had severe allergic reactions before, your healthcare provider may suggest you carry epinephrine. This medicine is available as an injector that you carry with you.

Outlook / Prognosis

What can I expect if I have skeeter syndrome?

Skeeter syndrome may last from a couple of days to a couple of weeks. You can go back to work or school when you feel well enough.

Living With

When should I see my healthcare provider?

See your healthcare provider if you’re bitten by mosquitoes and have an extreme reaction. Get emergency help if you find your mouth or throat swelling or if you have trouble breathing.

Additional Common Questions

Can you outgrow skeeter syndrome?

In general, local allergic reactions to mosquito bites improve spontaneously over time with age, repeated bites or both.

A note from Cleveland Clinic

If a mosquito bites you and you develop severe swelling, pain and itching within hours of the bite, you may have skeeter syndrome. You should contact your healthcare provider. However, if you have trouble breathing or other more serious effects, you should get immediate medical help. You can help yourself in the future by making an effort to avoid mosquito bites. Use mosquito repellant, avoid mosquitoes when possible and wear protective clothing.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/13/2022.

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