Random overnight lip swelling after Juvederm -- is this an allergic reaction? (Photos)

The description of your symptoms may suggest a delayed allergic reaction to the filler. This type of reaction is unpredictable. I am not sure whether your photos are in between the episodes or at the time  of swelling. It seems that at the time of your photograph your upper lips is disproportionally fuller and there is overall asymmetry. The only thing to address it is another hyaluronidase injection in attempt to dissolve it all and possible oral steroids. Your injector will most likely find the solution and determine whether there is also a possibility of granuloma formation. Good luck!