What Causes Lump On Neck While Having Treatment For Bronchitis?

I ve had bronchitis for approx 2 months - it s a difficult strain to treat apparently, and I finished a course of doxycycline a couple of weeks ago, but the cough is lingering. i m not sure if it s connected, but i ve just recently noticed a few small lumps on the back of my neck and my scalp has been very itchy over the past few days. Have you any idea what this could be? Thanks