What Causes Soreness In Back While Having Painful Boil On Upper Back?

Hi I have a boil for a few week on my upper back at my spine. my husband tried to express it yesterday, where a lil pus and blood came out. however today my whole back seemed painful and sore. the pain is not where the boil is but the area surrounding the boil. I feel a strain on my back when I am moving my body or bending etc. Is it something serious?