Nov 19, 2011 – Now You See Them, Or You Might Not


How long after a person is bitten by a bed bug does it take for a bite mark to appear?


And therein lies the problem. The bite reaction from bed bugs can run the gamut from no reaction at all to a serious immune system reaction. Typically there is a bite mark that appears anywhere from 1 hour to 24 hours after the bed bug has fed, but for some people it may be delayed, and the reaction or bite mark may not appear for up to 2 weeks after the feeding episode. I know one local college professor who maintains a bed bug colony in his lab, feeding them his own blood on a regular basis. He tells me he has been bitten thousands of times and never has shown the slightest reaction to it. His wife, on the other hand, was bitten by bed bugs in a D.C. hotel a few years ago and had to seek medical attention to calm down the large bumps that appeared on her skin.

If we say what is normal, then normal would be that for most people the bite mark will appear within the first 24 hours, showing as a red bump that itches for the next couple of days. With a little luck and no excessive scratching it should, like a mosquito bite, then just go away. However, some people can exhibit stronger reactions as their immune system just hates that foreign protein (the bug saliva) that much more. For some it may lead to long term problems with their nervous system.
At this time there continues to be no evidence that The Common Bed Bug - Cimex lectularius - is capable of vectoring any pathogens to humans, despite what the media likes to publish now and then or all the incredible things you can read on internet Blogs. It is obvious that these bugs can ingest pathogens from an infected human, but there seems to be no mechanism for them to pass the pathogens along to another human. The unfortunate side to this is that many public health agencies continue to label the Common Bed Bug as NOT a public health issue. This is slowly changing as they recognize that there are many serious consequences to the presence of bed bugs in a home - sleeplessness, irritability, anxiety, etc.

View past Ask Mr. Pest Control questions.