What you have is more of a mark (post inflammatory hyperpigmentation) like what Dr Theng says. You should stop using it once the redness is gone so it already way pass that. Instead use a good moisturiser to reduce the chance of the eczema coming back.
Marks can lighten over time (may be long on the body depending on how chronic your eczema was) and if you find it too slow, you can use a suitable lightening cream or do laser but know that this may occasionally trigger eczema in itself so the doctor has to assess it.
How long you use steroids depends on where you use it on and the strenght you use it. Follow the advise of the doctors giving it as he knows the strenght and the area to be used. If it doesnt get better, go back and ask him for further instructions.
I typically dont like to use steroid creams on the body for more than 2 weeks if it is a moderately strong steroids as it can thin the skin. If it doesnt resolve, it needs to be reassess and some chronic eczema needs complex management and strategies rather than just slapping on prolonged steroids forever…Hope that helps.
