Sorry for the delay in responding. I didn't receive notifications of the new posts for some reason.
I'm taking 5 mg of Meribin biotin/day. It's a highly bioavailable form of biotin, and the brand recommended for profoundly deficient biotinidase people. It's very expensive, though, and probably overkill. I'm at the end of my last bottle now, and am going to switch to a less expensive form. I'll know pretty quickly if it doesn't do the job.
My functional medicine doctor ran my 23andme results through an analyzer that spit out a ton of "SNP" data. I'm highly mutated on my ALDH2 gene, which is a gene involved in alcohol metabolism. I'm almost certainly deficient in the enzyme it produces that is phase 2 of alcohol breakdown. Without enough of that enzyme, you'd be left with a substance called acetaldehyde cruising through your veins. It's effects are well-documented, and I'm sure this is the root of my problem with alcohol consumption.
Cardiovascular effects of acetaldehyde accumulation after ethanol ingestion: their modification by beta-adrenergic blockade and alcohol dehydrogenase inhibition - PubMed
Accumulation of acetaldehyde in blood was accompanied by marked increases in heart rate (53%) and cardiac output (78%) as well as by decreases in diastolic arterial blood pressure (19%) and peripheral vascular resistance (46%).
With regard to investigating histamine as a possible cause of problems, the best thing you can do is note your activity, especially with regard to what you've eaten, prior to a flare of symptoms.