That itchy sensation you feel after getting bit is the human body's natural reaction to mosquito saliva. This leads to the immune system producing histamines, which cause the nerves to itch due to increased blood flow.

Why do my bug bites itch for so long?

Now, a new study in mice suggests that your immune system could react to these allergy-inducing proteins for up to a week, potentially explaining why an itchy bite lingers so long.

Is it normal for a bug bite to itch for months?

An itchy papule or wheal may develop and persist for several days. Eventually, most people become immune and insensitive to the saliva after receiving a number of bites. Allergic reactions to insect bites do not normally last more than a few hours, but sometimes they can linger for months.