Suggest Treatment For Red Colored Rashes On Chest, Back And Neck Area Of An Infant

My baby is three month old and she has rashes in her chest back neck and below the ear its like red colour pimpiles in small small area is it eczema or any kind of allergy. The first doctor told us she has eczema and pproscribedQV cream and primilan syrup. But after using it rashes increased so we consulted another doc and he prescribed dermocal lotion but its not fully vanishedis this lotion safe for infants and is primilan is safe pls give me answer