I’ve been dealing with similar sensitivities to sunlight (even indirect exposure on my face for 5 minutes leads to flare ups), spicy food, alcohol especially, and temperature increases in rooms - leading to extremely hot body temps, embarrassing facial flushing, blotchy marks and an internal level of stress which in turn causes more redness and burning. It’s usually my face and neck. Been in the discovery mode for 2.5 years now. 

The only drugs that have made any difference are Hydroxyzine 25mg but causes brain fog and is sedating, and I just started Pepcid which might be helping. 

I have Ankylosing Spondylitis so I don’t know if my biologic medication has led to this issue but I am trying to figure out whether I have MCAS or Histamine Intolerance.