What Causes Tightness Around The Neck?

Hi there, I am a working resonably active (we live on a dairy farm in NZ)45 yr old female, with Rheumatoid Arthritis for 23yrs, Cardiomyopathy, blood pressure related to the cardio & some food intolerances that I know of, but of late I have been experiencing tightness around my neck like I am wearing a tight collar & when it gets worse my ears tend to feel pressure to & I am told i go slightly red in the face, ears and neck like I am sunburnt but they are not hot to touch. I am on numerous medications for my pre-exsisting health issues & havent had any changes, I have just found Im intolerant to out organic grapes which aggravated the above symptom but none the less it is still there do you have any ideas. I dont feel like I am anxious well not that i know of.