What Causes Painful Nodules In The Tattoo Area?

I recently received a new tattoo, 3-4 weeks ago, and everything was under sterile conditions. I am a medic with the military, however I am completely lost on what these sxs could be from. I have been receiving random areas of folliculitis localized to the general area of my tattoo work. New nodules are noticed upon awakening as they are painful opposed to normal folliculitis. Any ideas?