For most people, the bite is the first indication of a bed bug problem.

Bedbugs normally bite people while they are sleeping. They get to your blood by piercing the skin and injecting a salivary fluid that causes your blood to flow easier (an anticoagulant) and also anesthetizes your skin, so you won’t feel the sting, immediately wake up, and crush the little vampire.

It is that saliva (or rather, the proteins in the saliva) that causes an allergic reaction in most people. The reaction causes redness, swelling, inflammation, and most of all, itchiness around the area of each bite.  The redness looks different on different people, and the can even vary in appearance depending on the location of the bite on your body. It might look like a mosquito bite, or a large red welt, or something in-between. Some people have reported that the bites have a white mark or depression in the center, though that is not always the case.

So your bites will look different from those of other people. To see the bites on various people, check this photo pool at Flickr: http://flickr.com/groups/bedbugs/pool/.

Here's a blogger who has posted pictures of her bed bug bites.

Reactions to the bites may be delayed. In fact, in some cases it can be a day or more before the welts appear. Once they appear, the welts shrink down to red spots, but those spots can last for days.

Bed bug bites are often in a little row, sometimes three or more, one right after another.

It is estimated that 20-30% of people do not have a reaction to bed bug bites. No itching, no swelling, nada. (Sounds nice, doesn’t it? Makes me wonder if these people become something like a bed bug Typhoid Mary – carrying the infestation with them, spreading it to new apartments and condos, but never suffering from the misery they bring to others).

For most people, though, bed bug bites itch. And it can be awful – they can itch so much that it becomes painful. I have heard of bed bug sufferers whose reaction to the bites grew worse and worse over time as they became more sensitive to them. That’s just another reason not to mess around with bed bugs. If you think you have them, you have to deal with the problem now, before your own body joins the fight against you.

Here is the one good thing about bed bug bites: As I mentioned before, they have not been implicated in the spread of disease. For some, that is a comforting thought. No matter how bad the bites get, and even though they might drive you crazy, there is no evidence that you can get anything really nasty from a bed bug bite. Of course, that’s one reason that the government is so slow to deal with this issue – they don’t see it as a public health crisis.