Does anyone know best cure for atopic dermatitis?

Moisturizer/steroid. There is no actual cure, unless specifically caused by an allergen or two (check foods, dust mites, etc). Focus on the dryness and the inflammation. Whether it's mild or severe, you should always use topical moisturizers (eucerin, aveeno, (oatmeal) even vaseline). Topical steroids will take care of the inflammation. The severity of the rash generally determines how strong it needs to be.