Can Usage Of Inhaler Be The Cause Of White Patches On Neck,back And Ears?

Hi my son is 7yrs of age ,he has been on treatment for asthma since 4yrs,of late he has developed white patches on his neck,back and ears.Is it an adverse effect of constant usage of the inhaler or due to any other reason.he also had ezcematic dermatitis at the age of 2.