Tender underarm area for over a year . had scan said reactive node . pain still present and node can still be felt ( not big enough to be noticeable ) but sore to touch . should this be biopsied ? seems to be worse when unwell but always tender?

If the node has not increased in size or new ones haven't cropped up this is somewhat reassuring that the node is benign. However since it remains tender it either gets irritated in a nonspecific way or is reacting to some localized inflammation but there seems to be no systemic illness present. Stop deodorants. I would consult a general surgeon to examine the axilla & lymph node and advise you.

You could watch and wait. You may feel the node every couple of weeks, if the lymph gland doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or you develop fever, or lose weight, you should see a doctor. Wish you good health!