The differential diagnoses includes ichthyosis, atopic dermatitis, exfoliative dermatitis, asteatotic dermatitis, or any process that causes dry skin, including inadequate use of emollients. Ichthyosis can be acquired or inherited in an autosomal dominant or recessive fashion. Ichthyosis vulgaris is the most common form of ichthyosis and presents with fish-like scale sparing flexural surfaces. Atopic dermatitis tends to be stimulated by irritants such as food or environmental allergens, leading to itchiness, redness, and scaling; skin of the anticubital fossa, popliteal fossa, feet, ankles, hands, wrists, upper chest, neck, face, and eyelids tend to be affected. Although atopic dermatitis is seen in all ages with varying symptoms correlated with age, it is most prevalent in younger patients, particularly infants and children. Exfoliative dermatitis or erythroderma may result from drug therapy, systemic or cutaneous disease, or idiopathic causes, and manifests as generalized erythema and scaling affecting almost the entire body. Asteatotic dermatitis is most commonly seen in elderly patients, as a result of decreased sebaceous and sweat gland activity, and tends to affect the shins, hands, and trunk. It can present with pruritus and appears as “cracked porcelain” with irregular scaling and polygonal fissures.

A complete history (social, family, environmental, exposure history; past medical history, medications). Important factors to note:

Conduct a focused physical examination, including thyroid and full skin exam

Biopsies are rarely indicated as dry skin can be easily diagnosed clinically. Histological findings include atrophy of the pilosebaceous follicles and eccrine sweat glands [16].

Patients should apply petroleum or non-petroleum based hypoallergenic emollients to moist or wet skin daily, and should be advised to avoid excessive hand washing or showering which strip the skin of natural oils [4]. Neutral-pH products or liquid cleansers containing petrolatum should be used instead of harsh antibacterial soaps. For scaly patches without fissures, lactic acid containing moisturizers are indicated. To ensure adequate hydration, a cool mist humidifier may be used during dry winter months. The diet should include adequate water intake, appropriate for a CKD patient, and adequate intake of essential fatty acids. Cotton clothing and bedding should be used instead of wool and other irritating fabrics.

Emollients aim to target the key abnormalities of xerosis, including inadequate water transport to the stratum corneum; poor water-binding; and barrier disturbances. Both classes of emollients, those comprising oil-in-water emulsions (light formulation) with 5 % urea and those comprising water-in-oil emulsions (rich formulation) with 10 % urea, applied twice daily over a 2-week period are effective in alleviating dryness and scaling [17, 18]. Table 6.1 includes a list of important emollient ingredients with specific roles in treatment of xerosis. Although a single emollient may not contain all of the listed ingredients, formulations combining ingredients which serve different purposes, such as humectants, physiological lipids, and natural moisturizing factors (NMF), are effective in treating xerosis [10]. A number of clinical studies have shown improvement in dryness with drugs containing urea, dexpanthenol, ammonium lactate, lactate, lactic acid, and/or pyrrolidone carboxylic acid as active substances (Table 6.2).