The Stages of a Mosquito Bite

Mosquitoes are tiny, winged insects and there are many different species. Female mosquitoes bite animals and humans because they need blood for the development of their eggs. Mosquito bites are usually harmless, but there is a risk of catching a mosquito-transmitted infection such as malaria in some parts of the world 3. Furthermore, mosquitoes can infect your household pets with heartworms. Help prevent mosquito bites by wearing insect repellent containing DEET, picaridin or lemon eucalyptus, and keep your skin covered with long-sleeved tops and trousers when visiting areas you are likely to be bitten 23.

Mosquito Bites

A mosquito has a specially-adapted mouth part, called a proboscis, which enables it to suck blood. It also injects saliva into your skin, which thins the blood and makes it easier to drink. Mosquitoes find a suitable person to bite by detecting carbon dioxide in exhaled air and the chemicals in sweat. You may be at greater risk of being bitten if you are male, have type O blood, are overweight or are wearing dark-colored clothing, according to the Mayo Clinic.

Redness and Swelling

A red, itchy, annoying lump, known as a papule, often develops at the site of a mosquito bite. This is caused by an allergic reaction to the mosquito's saliva. You may also notice a tiny hole in the lump where the mosquito bit you 1. The swelling usually lasts for a few hours and gets better on its own. Some people are more sensitive to mosquito bites and experience stronger reactions than others 3. The area surrounding a mosquito bite may become inflamed and filled with fluid – this is called a weal and may last for a few days, says NHS Choices 2. Mosquito bites can usually be treated at home and do not require medical attention 3.


Wash a mosquito bite with soap and water as soon as you notice you have been bitten – this reduces the risk of infection. Calamine lotion, witch hazel or other over-the-counter anti-itch perparations help stop the itching. Putting an ice pack or cold compress on the bite may also relieve the itch and reduce swelling. Never scratch a mosquito bite – this can make the itching worse and may cause an infection.


Mosquito bites can occasionally become infected and may require treatment with antibiotics 3. Infection may result from bacteria carried by the mosquito or from scratching a mosquito bite. Symptoms of infection include severe swelling or pain around the bite, pus coming from the bite, or swollen glands. Consult a doctor if you suspect you have an infected mosquito bite.

Allergic Reactions

Severe allergic reactions to mosquito bites, known as anaphylaxis, are very rare, but require prompt medical treatment, says KidsHealth 13. Symptoms may include severe swelling, a blotchy rash, feeling sick, dizziness, breathing difficulties or wheezing. Allergic reactions are usually associated with insect stings rather than bites 2.