What distinguishes bed bug bites from black widow bites?

Bed bug bites/spider: Bed bug bites are usually very itchy red bumps in multiple locations, often scattered around on the trunk and/or extremities. There's no pain. Black widow spiders leave only a tiny mark with 2 tiny holes in the skin initially, and there can be only 1 bite. After the bite, there is severe pain locally and in other parts of the body, nausea and vomiting, chills and abdominal pain.

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 hypersensitive blisters may occur. Telltale sign is linear track of lesions from sequential feedings – doesn't always occur. Bites are in areas exposed while sleeping-arms, shoulders, neck ; legs. A black widow bite can cause.