In infestations with persistent, repeated exposures, bed bug bites may appear in crops. Also, since bed bug bites usually take three to six weeks to heal, as long as the infestation is still present, new bites may accumulate even as the older ones start to resolve. Thus, people may have various bite reactions in various stages of evolution at the same time.
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.