You say a blueberry antioxidant product. Wouldn't it be worthwhile to try some mashed blueberries on the affected area at bedtime? Might get a few stains on the sheets. But on the other hand, if the cream you are using is not intensely blue, and also stain the sheets or clothing, it may be mostly ingredients other than blueberry. It is a credible idea that several different juices, used topically and/or taken orally could be of some benefit for some skin conditions, and for one's general health. I would favor using the fresh fruits themselves applied at bedtime, so that the enzymes which are natural to the fresh fruits will not have been denatured by pasteurization, as they most certainly will have been in a lotion, cream, or even a juice for oral consumption. The antioxidant effect should also be greater.
Be sure to avoid putting a dark colored fruit or juice on any open skin lesion. Would not want to accidentally tattoo the person.
As to wanting to know more about the product you are using, the ingredient list, exactly as it is on the container is always useful.
