My Daughter Had A Bad Cut From A Surfboard Requiring

My daughter had a bad cut from a surfboard requiring abut 35 stitches. the wound was quite deep. it happened on the 19th of march. when the stitches were removed 10 days later the wound partially opened up. We went to emergency and they did not feel the wound was infected and that the wound would have to granulate up which it seems to have been doing. While the wound looks like it is healing. No redness around the wound itself she has a red hot hive rash to the left of the wound that appears to be getting worse. the rash is raised and hive but not blistery. It is hot to touch and can be sore at times.