This kind of hypersensitive reaction from insect bites differs from person to person. It can be a severe asthma attack or something like facial swelling. Bites from mosquitoes usually give rise to lumps, wheals and swelling that goes away within a day. These are localized reactions that do not need a visit to the doctor for treatment. People who are sensitive to insect bites or those with compromised immune system are at increased risk of developing severe reaction after being stung.