The insects most likely to bite humans in Indiana are mosquitoes, flies, fleas and more recently bedbugs. Most blood feeding insects that pierce the skin have salivary secretions that are injected into the bite area. These secretions typically contain anti-coagulants, proteins and other factors that prevent the blood from clotting and blocking the feeding tube or digestive system of the insect. When the insect finishes feeding, it leaves behind proteins and other feeding secretions that can trigger an allergic reaction. The red itchy bump on the skin results from the human immune system recognizing and removing the proteins.
Most allergic reactions are mild, accompanied by a small red bump on the skin, and dissipate in an interval of a day or less. Insect bites that get attention of the medical community typically cause more severe immunological effects such as anaphylaxis or are secondarily infected by other pathogens.
What to do for an insect bite? There is a lot of anecdotal evidence but what about scientific studies? This topic is reviewed in Drug and Therapeutics Bulletin (DTB 2012;50:45-48 doi:10.1136/dtb.2012.04.0099 ) “Management of simple insect bites: where’s the evidence?” The article notes the need for controlled studies and that current recommendations are primarily based on clinical experience and expert opinion. The need for controlled studies is clear because many of the reported symptoms of insect bites disappear after a brief period with no treatment at all. There is very little evidence to suggest that over the counter products applied to mosquito, fly, flea or bed bug bites are effective. Millions of dollars are spent on home remedies each year for products to treat insect bites and stings. For most insect bites, the evidence suggests that consumers should save their money, ignore the bites and let them go away. Applying OTC products to insect bites may cause consumers to be bit twice, once by the insect and once in the wallet.