Do Mosquito Bites Release Histamine?

Several studies have investigated the question, “Do mosquito bites release histamine?” The results of these studies suggest that yes, histamine is released in human skin after a mosquito bite. The chemical is produced by the immune system, and it increases blood flow around the bite site. It also causes inflammation and swelling. When the body is overloaded with histamine, it can cause redness and swollen skin.

Researchers at the Helsinki University Hospital have studied the release of histamine after mosquito bites. They found that the highest concentration of histamine is released in the 30- to 45-minute fraction after a bite. The concentration of histamine dropped rapidly in the next 60 minutes. Histamine has an anticoagulant effect, which may increase the pressure in the feeding site and decrease hemostasis.

The study used six mosquito-sensitive subjects to observe the reaction to their mosquito bites. One subject showed a marked increase in histamine after two hours, while three of the other subjects had slightly elevated levels during the same time period. These findings indicate that the immune system is hypersensitive to mosquito saliva.

Researchers have identified proteins in mosquito saliva that are involved in triggering an itch response. They include D7 proteins, which bind to biogenic amines, like histamine. This may inhibit the allergic response and reduce the itch sensation.

However, histamine is not the only compound released in a mosquito-bite reaction. New research has discovered that there is a peripheral pathway that releases other substances.