This is the English version of guidelines for the management of asteatosis 2021 in Japan. Asteatosis is a synonym of xerosis found in a wide range of diseases that induce dry skin through impaired functions of either water retention of the stratum corneum or skin covering with acid mantle. Patients with asteatosis may be accompanied by pruritus. Moisturizers are the first-line treatment for asteatosis and their adequate use must be recommended. The main purpose of the present guidelines is to define skin symptoms requiring treatment with moisturizers for medical use in patients with asteatosis. If the deterioration of marked scaling or scratch marks is predicted, therapeutic intervention with moisturizers for medical use should be considered even in the absence of pruritus. Regarding six important points requiring decision-making in clinical practice (clinical questions), we evaluated the balance between the benefits and harm of medical interventions in reference to previous reports of clinical research, and presented the recommendation grades and evidence levels to optimize the patient outcome by medical interventions.