Redness two days post dermal filler injection? (photo)

I had a juvederm voluma injected at the tip and bridge of my nose. I have done this before and happy with the result. However, after two days of the injection the bridge of the nose began to get red but not swollen. My doctor gave me antibiotic. Now it's the 6th day, although it begins to go away, it is still red. How could the redness appeared after two days post injection? And only at the bridge, the tip of the nose is fine.