I Have Primary Immune Deficiency, Which Is Genetic In Me

I have Primary Immune deficiency, which is genetic in me and affects any and all parts of my body.I bumped my arm bone by my wrist Friday night and it swelled up into a very large bump, it's now 4 days later and the bruising is spreading down my arm and up into my hand and fingers it feels like the blood vessels are breaking it will hurt and itch and then more bruising appears.I am at the moment on Prednisone and Keflex for an upper respiratory infection, could either of these medications cause this?