Frequently, the first evidence of the presence of bed bugs is the sudden appearance of very itchy bed bug bites on your torso. It is important to seek medical attention if bites alone are the only evidence of bed bugs. Your doctor may recognize skin rashes, allergies and other conditions that are not insect bites.There are several other insects and arthropods that will produce itchy welts very similar to bed bug bites. This is because mosquitoes, fleas, lice, mites and bed bugs all inject saliva during the feeding process to thin human blood. This blood thinning material is largely responsible for the “itchiness” of bites. Individuals vary greatly in their response to different insect and arthropod saliva and over time some individuals may become either more or less affected.