What are the differences between a spider bite and a bedbug bite?

Depends: For a general spider (not dangerous to humans) and bedbugs, the bites can look similar with redness, swelling, warmth, initial pain which fades quickly, and itch. Bedbugs sometimes bite in a linear fashion - thus leaving a line of bites. That's the only way i know to differentiate.

Spiders vs bedbugs.: Bed bug bites may have no sx's/signs except for 2 small skin puncture points. A reaction may show from an hr to several days later. It can cause itchy, pink, swollen, lesions w clear center. If hypersensite blisters may occur. A telltale sign is linear track of lesions from sequential feedings – but doesn't always occur. Bites are in areas exposed while sleeping-arms, shoulders, neck ; legs. >.