My son is 5.5 months old. We have started giving semi solids to him. But he got severe rash and blisters from cows milk. Can we continue giving him nan pro 1 which he was taking since 4 months of age? Also which ointment we should apply? We r using siloderm and giving him zerolac. But the rash is increasing. Please suggest. Its been 4 days now no relief lots of small blisters are forming in his nappy area. We r only using cotton nappies and keeping the skin clear and dry.