Hi, I had gone through your question and understand your concerns. You should be worried but not too much. The blotches are simply our skin s way of reacting to certain irritants, infections,allergens or hormonal changes. Children are more sensitive to chemicals, viruses and bugs than we are. The blotches can be sign of sweat rash, eczema, impetigo, skin infection. Because it can be difficult to distinguish one type from another, you can discuss it with a pediatrician or pediatric dermatologist. If your baby has itchiness we should exclude contact dermatitis, eczema, fifth disease, impetigo, poison ivy, scarlet fever. The most common cause is allergy,i suggest: -Fenistil- single dose=amount of drops =amount of kg of baby three times daily. -Hypoallergenic diet to breastfeeding mother and baby. If it is just sweat rash-use antifungal Candid powder. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you and baby good health.