Dry skin behind the ears may be dry scales. There are several possibilities for dry scales, the most common being seborrheic dermatitis, especially dry seborrheic dermatitis, and if dryness occurs later, these fine, greasy scales may manifest as dry skin. It may also be scales formed by fungal infections, and such scales are usually mainly due to fungal infections that cause flaking reactions on the skin surface, so large patches of keratinous proliferation and shedding occur. It may also be eczema, especially chronic eczema, and some chronic eczema may lead to certain hyperplasia and scaling of the skin, accompanied by varying degrees of dryness and flaking symptoms.