Seborrheic dermatitis begins as reddish macules that are covered by subtle scale-crusts. In time, slightly elevated papules come into being and they may be associated with scale-crusts that vary in amount from hardly noticeable to striking. Once lesions of seborrheic dermatitis arise, the tendency is for them to wax and wane, but to persist nonetheless for the life of the person who bears them, expanding ever so slightly but relentlessly. The inflammatory process worsens very slowly, but progressively. First it tends to involve the skin above the nasion near the eyebrows, the malar eminences, and the paranasal folds. Over the course of years it may come to involve most of the forehead, the entire malar region, the paranasal and nasolabial folds, the postauricular regions, and the sternum. How extensive seborrheic dermatitis may become cannot be predicted, but it can be foretold that it will not involute in the absence of therapy.