Hi Doctor I Changed My Baby Milk From S26 Gold

Hi doctor I changed my baby milk from s26 gold to s26 promil now he's having a problem of yellow blisters under his feet and they are very scary and itchy I don't know if it's the recent milk he's drinking or its just normal because I changed his milk. Please advise because I went to a doctor he gave me viocort cream but it's not working the blisters keep on coming out on the whole feet and it seems very painful the way I see him scratch the feet and it's hot when I touch the feet
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