The papules or the bites travel along the bug movement ,that is why a generalised rash does not have the typical feature of cimicosis,as in your case.
When you say linear, how straight are you referring? For example, will it really look like a staight line or "somewhat" of a straight line? So if my entire bottom part of my arm has a "rash", then there's a good chance it's not bed bugs?
Bed bug bite otherwise known as cimicosis rashes come in a linear fashion in rows mostly on exposed part of body.This does not look typical.