Bedbug bites typically are stealthy and not felt by the host. This is because they inject a numbing substance into the skin along with an anticoagulant agent to prevent blood from clotting at the feeding site. Itchy, red bites on the skin may be the first sign you've been bitten. Bites are most common on the arms and shoulders, and the bites often occur in straight rows, as pictured here.
Some bed bug species are parasites of bats or birds, and may bite people if the wild hosts are no longer available. Although similar in overall appearance, the species of bed bugs that normally feed on bats, swallows, chimney swifts, pigeons or other wild hosts can be differentiated from those that prefer humans. Entomologists and knowledgeable pest managers can make this determination. If bat bugs or bird bugs are present, roosting and nesting sites should be the primary focus, and the animals should be removed and excluded from the building.
The bites themselves don't usually pose any major health risk since bedbugs are not known to spread diseases, but an allergic reaction to the bites may require medical attention, CDC officials say. There have also been some strange cases linked to bedbug infestations. Researchers reported in the Canadian Medical Association Journal in 2009 that they treated a 60-year-old man for anemia caused by blood loss from bedbug bites. Another study published in 1991 in the Journal of the Egyptian Society of Parasitology found that people with asthma might be more susceptible to allergic reactions from bedbug bites.
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.