Hives at night: Alpha-gal syndrome?

For the past five nights, including tonight, I have been experiencing a reaction of some sort. I assume that they are hives. The weird thing is that it only happens, well 95% of the time, the breakout starts in the evening. I know it's not from a bite or something because they are in different spots each night... I have had an allergy test ..that was done a few years back and it came back negative. Not allergic to anything. I know that can change, but I just find it odd that this only happens at night. During the day, I am fine... just anxious know what's to come after sundown. Another thing I noticed is that they are usually in straight lines.. not always, sometimes they are blotchy but a lot of the time they are in lines. I have taken benadryl every night for the past few nights... didn't work. Tonight I got a little bit of relief but I can already feel my body getting itchy. Hydrocortisone creams do nothing. I think I just apply them for piece of mind. I called my primary's after hours answering service and spoke with my doc. I have an appt with her in the morning and she is going to do bloodwork and give me steroid shots, but I just wanted to see if anyone else has experienced anything like this before or know someone who has.

They usually last for the night. When I can finally get myself to sleep at night.. in the morning i am fine. They dont leave any markings or anything. They are just red and raised and extremely itchy.

Any input will help. Thanks in advance.