The best way to confirm that the bites are from bed bugs is to find other evidence of a bed bug infestation. Common telltale signs can be found on or near your mattress: pull up your sheets and check the seams and folds for thin black fecal streaks or small red blood spots. You might also find bed bugs, living or dead, and their discarded shells in various hiding places, such as the joints of your bed frame.
Unlike those of other insects, bed bug bites may sometimes appear in tight lines of multiple, small, red marks where multiple bed bugs have fed along an exposed area. Bed bug bites can cause itchiness. Initially, a victim may detect a slight burning sensation. The burning area then develops red bumps, known as papules or wheals (rash). In extreme cases, bites may swell dramatically or turn into blister-like skin inflammations.