"Good night, sleep tight, don't let the bed bugs bite" is, when you think about it, a pretty awful thing to say to a child right before you expect her to fall asleep. Bed bug bites are itchy, occasionally painful, and can look like anything from a white raised welt (like a mosquito bite) to a rash, to large red welts on the skin.
If you have bed bugs in your home, you can't stop them from biting; they live off your blood. But there is a lot you can do to alleviate the discomfort, including getting rid of the bed bugs themselves.
Stop the allergic reaction. Bed bug bites itch because you're allergic to the substance the bed bug injects into the bite to delay blood clotting. A topical allergy cream such as Benadryl or anti-allergy pills such as Benadryl capsules should help the itching. Apply the cream or take the pills according to the directions on the package.
Cut the itch. For small children or other people who cannot take Benadryl, dab some white vinegar on the bites. The vinegar should dissolve the "itchy" chemical, and the slight sting should stop the itch.
Put the bites on ice. For instant relief, apply an ice pack to the affected area.
Lessen the number of bites. Less bites equal less itching, and there are things you can do to survive until the exterminator arrives. One is to frame your mattress top with double-sided tape. The bed bug will be stuck on the tape on its way to you and can't bite you. Another solution is to place your mattress in a mattress cover or mattress bag. This is not a mattress pad that keeps the top of your mattress clean and dry; this is a huge fabric or vinyl, zippered sack that covers your entire mattress--and traps the bugs inside where they can't get to you.
Warning
Some sources suggest using calamine lotion on bed bug bites. However, calamine lotion can dry out the surrounding skin and exacerbate the itch.