Flu, and now knee bumps?

Patient: Hi, I was wondering if I could get a little help. I recently got the flu and am slowly recovering from it. I visited the doctors yesterday for my symptoms and an ear infection and was given a few medications to take. My problem occurred this afternoon however, I went to lean on my knee when I noticed a small dull pain. As I examined what I thought to be a possible bruise, I found a small and growing red bump on my knee. I wouldn’t have been as concerned with this, but now I’m starting to have these small bumps on both of my knees. They’re slightly raised and tough feeling as well as warm. They hurt slightly when pressure is placed on them, and now starting to hurt when I stand and walk. I don’t think it’s an allergic reaction to the medicine, but is there anything else that could be causing this?

Symptoms: Slight pain and swelling in knees