Here is a really good link with pictures:

http://doyourownpestcontrol.com/bedbugpictures.htm

Anyone can get these nowadays. The link shows where they can hide.

Chiggers can cause bites too, but are really too small to see. Their bites cluster. My son used to get these, when he was young and getting into piles of leaves, dirt in playgrounds etc. Once he had them all over his stomach.
http://insects.suite101.com/article....arasitic_mites

Scabies can be hard to diagnose. Many of the original bites can occur on the hands, back of the knees. But people then get allergic reactions to them all over the body, and these may be hive like and are very itchy. So the hives don't look like scabies, but the scabies may be elsewhere on the body.

I recall a embarrassing story a colleague told me. Her son had an ear infection so she took him to the doctor. After examining him the doctor turned to her and said "By the way, your son also has scabies". She was mortified that she didn't know it, and that he caught it. It could be all over her home by now!

Have you had chicken pox as a kid? If not, it could even be chicken pox!

Sometimes these things are hard to identify.