My LO has been on an EHF formula for suspected cows milk allergy since Saturday so for about 4 days now however I want to ask how long did it take for your LO’s allergy rash to go away when they started a formula made specifically for CMPA. My GP has told me to wait at least 2-4 weeks before contacting them again unless it gets worse however I haven’t noticed any big difference as of yet. The rash continues to fade and then flare up and then fade again like a continuous cycle. Can anyone tell me how long it took for their baby’s allergy rash to go away?? It would give me a good idea as to whether the milk is actually working or not.