Symptoms may not appear until some days after the bites have occurred. Reactions often become more brisk after multiple bites due to possible sensitization to the salivary proteins of the bed bug. The skin reaction usually occurs in the area of the bite which is most commonly the arms, shoulders and legs as they are more frequently exposed at night. Numerous bites may lead to an erythematous rash or urticaria.
Jump up ^ Johann Friedrich Wolff; Johann Philip Wolff. "According to Scopoli's 2nd work (loc. cit.), found in Carniola and adjoining regions. According to Linnaeus' second work on exotic insects (loc. cit.), before the era of health, already in Europe, seldom observed in England before 1670". Icones Cimicum descriptionibus illustratae. p. 127. Retrieved 1 December 2016. fourth fascicle (1804)
However, low-level infestations are also much more challenging to find and correctly identify. Other insects, such as carpet beetles, can be easily mistaken for bed bugs. If you misidentify a bed bug infestation, it gives the bugs more time to spread to other areas of the house or hitchhike a ride to someone else's house to start a new infestation. Learn about identifying bed bugs.
One bed bug will usually take more than one bite. Once a bed bug inserts its mouthparts and finds a suitable blood vessel, it will begin feeding. However, finding the right blood vessel may take more than one injection into the skin. In addition, bed bugs are very sensitive to movement by the host they are feeding on. Therefore, if a sleeping person moves, a feeding bed bug will probably withdraw its mouthparts and begin its search for a blood meal on another part of the body. It’s important to remember that the number of bites a person receives is not indicative of the number of bed bugs that feed on that person.