Why do mosquito bites itch

The mechanism and body response to a mosquito bite is fairly simple. First, virtually all mosquitoes that bite are female as they need to feed copiously when pregnant in order to properly develop its young and ensure a successful spawning. When the female mosquito bites she leaves behind anti-coagulant saliva which serves a useful purpose for the mosquito, as it enables her to extract blood rapidly without attracting attention. Once injected by the mosquito the saliva causes the body to produce a histamine, or slightly allergic, response. It is this slightly allergic response that causes the skin around the bite site to become inflamed and itchy.

Although the initial reaction may cause discomfort and irritation this bodily response may actually be viewed as beneficial. If you get bitten in an exotic location where the spreading of diseases like malaria or sleeping sickness is common (or even in parts of the US, where West Nile Virus is present) is it is important to seek medical help immediately if you start to present flu-like symptoms a few days or weeks after having been bitten. As the itching sensation alerts you to the fact that you have been bitten you can inform your doctor of this and receive the appropriate – and often lifesaving – treatment as necessary. Without this bodily response you may remain in ignorance of the bite, and this can cause a dangerous delay in the treatment of any later symptoms.

If you regularly spend time in a mosquito-infested region and get bitten frequently you may build up an immunity to the saliva over time and may not be afflicted by the swollen, itchy blots that accompany mosquito bites. This immunity can wear off if you then avoid exposure to bites for an extended period of time. Remember, a lack of allergic reaction to the bite does not confer immunity from the various diseases transmitted by mosquitoes.

Children also typically display a stronger reaction to mosquito bites than adults, so be sure to cover your children’s skin – especially at dusk and dawn as these are the times when mosquitoes are most active. The severity of reaction to mosquito bites can also vary from person to person, and some people may exhibit strong allergic reactions. It is important to remember that such a reaction is not usually an anaphylactic reaction such as is caused by the venom in a bee sting to those allergic to it. It simply means that the skin may discolour more that usual and may present scabs, blisters or bruises. This can cause concern in children as it can resemble the dermatologic symptoms of chicken pox, therefore careful inspection is necessary in determinig the cause in some locations.

Whether adult or child it is important to remember not to scratch too much, as this can open the scab and cause bleeding and infection of the bite site. Ensure that you keep the site clean and apply antihistamine cream to reduce the intensity of the itching as necessary. You should also ensure to keep the area as cool as possible to reduce inflammation and itching. Camomile lotion is particularly good for this.