If the formula is new in the last four days I would hang fire a bit, usually you need to give a good couple of weeks to see what the effect of a change is going to be. Often reflux and cows milk protein intolerance/allergy (CMPI) go hand in hand, and eczema is a common sign of CMPI. Nutramigen is what is known as a hydrolysed formula where the cows milk protein is broken down quite extensively to a point where in most babies it no longer causes an allergic reaction. If her skin has cleared up already on the new formula that could well be a good sign but it may be you need to wait a bit longer to see the full effect on the reflux. I wouldn't change to similar sensitive, as I understand that's a lower lactose formula but will have the normal cows milk protein in it, so more likely to cause issues. Lactose intolerance is actually pretty rare in babies compared with CMPI but often gets confused. If after a couple of weeks there is no change in the reflux but the skin is improved then it may be as Bec said that additional treatment for reflux is required on top of the hydrolysed formula to manage any CMPI that may be present. There are lots of anti-reflux medications, often the things a doctor will try first like positioning upright after feeds, Gaviscon etc will not be enough for babies like yours (potential CMPI and premature) and you may need to go down the route of a PPI such as omeprazole. I'd give it a week and then pop along to your doctor for a chat x
