What Causes Aching And Swelling Under Armpit After Using New Deodorant?

i am 35 years old..i have started to use a new deodorant a week ago (Rexona) and four or five days after i expeienced a sharp pain in my right arm pit. i looked at in the miror and it was clearly swollen.. the Sharp pain lasted for a few minutes only but now it is like aching and i have someithng like a cold feelind in the arm pit , the side of the breast and a little behind the shoulder. what could it be.. can it be infection from the deodorant