We are in the middle of the mosquito season here in Central Ohio. I had a request via Facebook to discuss this topic. What follows is information about prevention of bites, treatment of bites, and diseases that concern us that are transmitted via mosquito bite.
The two major infections we worry about from mosquito bites are West Nile Virus and the group of encephalitis-causing viruses (arboviruses). Both are uncommon enough that we see very few cases of these. I do not know of a single case of confirmed West Nile Virus illness in a patient at Hilliard Pediatrics. I am aware of a few children in our practice who have had a mosquito-bite related encephalitis. Therefore, please realize that the chance of a life-threatening illness from a mosquito bite is very, very small. Having said that, the chance of being infected from a mosquito bite is greatly reduced if you use good bite-prevention.
There are at least 175 species of mosquitoes in the US. The female mosquito bites us (the males do not) because they need blood to develop fertilize eggs. As experience tells you, some people are more prone to bites from mosquitoes than other people. Scientists are still studying what it is about some people that attracts the bites, but it is known that carbon dioxide released from the skin attracts the mosquitoes. Some people release more from their skin than others. Scientists believe 85% of this "mosquito magnet"issue is genetic.
To reduce the possibility of being bitten, regularly use an insect repellent on exposed skin; wear long-sleeved shirts, long pants, and hats to cover exposed skin; avoid being out in the early morning and in the evening; and consider applying permethrin-containing to clothing, shoes, tents, and other gear.
There are different insect-repellents. For children less than 2 months of age, drape their carrier or bouncy seat with mosquito netting. For children 2 months of age and above, DEET and picaridin are excellent repellents. Both have been extensively studied. This link to the CDC website is a good resource about the insect repellents. I recommend the DEET-containing or picaridin products for children 2 months and above. Although concerns have been raised over the years with the toxicity of DEET, the risk is very, very low AND the potential risk of being unprotected is real. The higher the concentration of DEET, the longer it lasts (for instance, 5-10% lasts about 2 hours while 20-30% lasts 5-6 hours). The CDC also has a Frequently Asked Question page about insect repellents. The American Academy of Pediatrics states that DEET is safe for children 2 months and older if used as recommended. If one product does not protect you and your child from insect bites, try a different product or stronger concentration.
For the mosquito bites themselves, try your best not to scratch the bites, use an anti-itch cream or gel (over-the-counter hydrocortisone cream, Itch-X gel, and Calamine or Caladryl are all helpful), and use oral diphenhydramine (Benadryl) if the itching is not well controlled by one of the creams or gels, and expect that the bites should gradually fade away over a few days to a week. The bites can last longer if repeatedly scratched. It is rare for the bites to pick up a bacterial infection. If that happens, it will have a crusty discharge, be tender, and more red.
Many people become mildly allergic to the bites of some species of mosquitoes. It is very, very rare to see someone have trouble breathing (a worse allergic reaction). The mild allergic reactions have large (even 6-7 inches across), red, warm, itchy areas that often need oral diphenhydramine (Benadryl). Cool compresses often help also.