What Causes Rashes And White Patches On Infants?

Sir/Madam, due to lack of breast milk am giving infant feed (Novalac1) and breast milk also. Now baby is 2+ months old. Last week onwards skin rashes are coming on his body and also two - three white spots on his face.Am using Sebamed soap and cream and sometimes Johnsons powder also. Please advice.

Thanks in advance.