Xerosis, also referred to as dry skin, affects 30% to 99.1% of people older than 60 years.1,2 Xerosis is usually caused by a lack of epidermal lipids and is the most common cause of pruritus in the older adult.2,3 Pruritus can result in excessive scratching, skin injury, skin tears, wounds, secondary infection, discomfort, and pain and can have a considerable impact on quality of life.3 Although all areas of the body may be generally affected, sites with fewer sebaceous glands, such as the lower legs, forearms, hands, and feet, are more frequently affected.2
Xerosis predominantly affects the outermost layer of the epidermis, the stratum corneum (SC), which serves as a barrier to the external environment, providing protection against water loss.3 The SC is composed of corneocytes, which are terminally differentiated keratinocytes that contain natural moisturizing factors (NMFs), such as urea, lactic acid derivatives, pyrrolidine carboxylic acid, amino acids, ammonia, uric acid, and inorganic salts and sugars. These NMFs act as humectants (they attract and bind water to the skin), promoting skin plasticity, optimum skin barrier function, and healthy shedding of skin cells (desquamation).4 Corneocytes are embedded in a lipid matrix consisting of ceramides, fatty acids, and cholesterol. The lipid matrix prevents water evaporation and is responsible for the chemical barrier of the skin.2 The SC needs a minimum water content of 10% to remain pliable and avoid fissures.4
Risk Factors
In the older adult, xerosis results from a complex interplay of age, health, environmental, and lifestyle factors (Table). As the body ages, epidermal cell renewal and sebum production decline, levels of filaggrin (a protein that derives NMF components) decreases, and transepidermal water loss (TEWL) increases.2,3 These changes in aging skin, combined with environment and lifestyle factors, produce structural and functional disturbances causing xerosis.3
Symptoms
Visual signs of xerosis include dry, scaly, rough, and grayish skin.2 In addition, the skin is characterized by decreased elasticity, coarse texture, wrinkling, erythema, and fissures (Figure).2 An individual may feel skin tightness and itching, which can be perceived as pain or a burning sensation.2
Prevention and Management
The overall goal of xerosis management is to restore normal skin barrier function, soothe affected skin, and reduce itch and scratching to prevent further damage.3 Patients should (1) avoid aggravating factors, (2) promote epidermal hydration, and (3) repair barrier function. The following practical strategies may support these aims:
* Bathing in lukewarm water for 10 to 15 minutes, followed by immediate application of moisturizer to the skin (within 3 minutes).
* Replace harsh skin cleansers with gentle substitutes (soap-free, fragrance-free cleanser or bath oil)
* Avoid friction from washcloths, rough clothing, and abrasives
* Ensure adequate nutrition and hydration
* Use a humidifier to ensure a relative humidity setting of 45% to 60%
* Use hypoallergenic products and avoid fragrances and common allergens, such as lanolin and nut oil products
* Refer to healthcare professionals where appropriate2,3,6
Topical Treatment
The use of leave-on skin care products is the mainstay treatment for xerosis. The aim of skin care products is to restore the structure and function of the epidermis, improve skin barrier functioning, decrease TEWL, reduce inflammation, and decrease itch.3
Various leave-on skin care product formulations are available. These products can be categorized into three classes: (1) emollients, which soften and smooth the skin with ingredients, such as naturally occurring oils, fats, and waxes; (2) occlusives, which create a film on the skin surface and reduce TEWL and include petrolatum jelly, liquid paraffin, and wax or silicone-derived products, such as dimethicone; and (3) humectants, which bind and hold water in the SC, and include urea, glycerine, lactic or glycolic acid, and hyaluronic acid. An ideal leave-on skin care product should, as much as possible, mimic the components of the skin barrier and SC.2 However, based on current evidence, it is unclear if one product or ingredient is superior to another; rather, it is the regular application of a leave-on skin care product that likely improves xerosis.1
If the skin is erythematous or if there is pruritus, additional ingredients with antipruritic properties should be recommended.2 Plant-based additives, such as oat extract, have been shown to reduce pruritus intensity.2 Further, bases with a higher water content and refrigerated products can help soothe intense pruritus.2
Leave-on skin care products should be routinely and liberally applied to the affected areas of the body by gentle rubbing into the skin. Using leave-on skin care products, particularly after bathing, will help trap moisture in the skin.5 Importantly, clinicians should make patients aware of the increased risk of falls with product application to hands and feet because of reduced grip, and prevention strategies should be considered to ensure safety.5
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