Some patients develop blisters filled with blood or bloody fluid, especially on the arms and legs. These blood blisters are extremely rare and can burst, causing bleeding or oozing of the bloody fluid. Healthcare providers are not sure if the cause of these blisters is related to the bug or the human but have found groups of patients that were all bitten by bugs on the same train exhibiting this sign.
The size of bed bug bites varies with a number of different factors. Bed bugs inject an anti-coagulant along with their saliva when they pierce the skin to take a blood meal. This anti-coagulant is mostly responsible for how a person reacts to the bite and determines the size of the bug’s bite. Since people will have various sensitivities to the bed bug’s bite, the size of the bite will vary, as well. Another factor that influences the size of a bed bug reaction is the number of times a person is bitten. Bite reactions of people bitten many times are also variable, and their response may be either more or less intense as the number of bites increases.