Mosquito Bite Symptoms and Treatment

Female mosquitoes bite people and animals to get a blood meal. Most female mosquitoes cannot produce eggs without a blood meal. Male mosquitoes do not bite people and animals.

What Happens When a Mosquito Bites You

Mosquito biting a person to get a blood meal

Mosquito biting a person to get a blood meal. The body reacts to the mosquito saliva after the mosquito finishes its blood meal.

When a mosquito bites you, it pierces the skin using a special mouthpart (proboscis) to suck up blood. As the mosquito is feeding, it injects saliva into your skin. Your body reacts to the saliva resulting in a bump and itching.

Some people have only a mild reaction to a bite or bites. Other people react more strongly, and a large area of swelling, soreness, and redness can occur.


Mosquito bite signs include:

  • A puffy and reddish bump appearing a few minutes after the bite
  • A hard, itchy, reddish-brown bump, or multiple bumps appearing a day or so after the bite or bites
  • Small blisters instead of hard bumps
  • Dark spots that look like bruises

More severe reactions can occur in:

  • Children
  • Adults bitten by a mosquito species they haven’t been exposed to previously
  • People with immune system disorders
Mosquito bite on the back of a boy’s neck.

Mosquito bite on the back of a boy’s neck. Credit: Getty Images.

People experiencing more severe reactions may have the following signs:

  • A large area of swelling and redness
  • Low-grade fever
  • Hives
  • Swollen lymph nodes


  • Wash the area with soap and water.
  • Apply an ice pack for 10 minutes to reduce swelling and itching. Reapply ice pack as needed.
  • Apply a mixture of baking soda and water, which can help reduce the itch response.
    mother apply antiallergic cream at baby knee with skin rash and allergy with red spot cause by mosquito bite

    Anti-itch cream for a mosquito bite. Credit: Getty Images.

    • Mix 1 tablespoon baking soda with just enough water to create a paste.
    • Apply the paste to the mosquito bite.
    • Wait 10 minutes.
    • Wash off the paste.
  • Use an over-the-counter anti-itch or antihistamine cream to help relieve itching. Follow the product label directions.


Infected bite

  • Do not scratch bites. They can become infected.
  • An infected bite may appear red, feel warm, or a red streak will spread outward from the bite.
  • See a healthcare provider if symptoms worsen.

Mosquito-borne diseases

  • Mosquitoes spread germs through bites. Viruses like West Nile and dengue and parasites like malaria can make you sick.
  • A mosquito gets infected with a virus or parasite when it bites a person or animal that is infected. The infected mosquito can spread germs to other people or animals through bites.
  • Not everyone infected with a mosquito-borne germ gets sick.

Prevent Mosquito Bites

You can protect yourself and your family from mosquito bites.

Treat clothing and gear with permethrin.

Treat clothing and gear with permethrin.


Activity Book for Kids – Mosquito Bites are Bad!