US Pharm. 2006;4:28-32. 

Dryness of the skin, known as xerosis, or xeroderma, is a common condition in the elderly. As people age, the outer layer of skin loses water, causing the surface to become dry and rough.1 Incidence of xerosis increases with age, and prevalence of the condition in the United States may increase, given the demographic aging of the population.2 Xerosis may be a troubling condition in elderly individuals because of its physical appearance and the physical discomfort that may ensue. While the exact cause of xerosis is unknown, the condition is related to altered lipid composition of the stratum corneum, in addition to other changes in epidermal differentiation.1 It appears as though xerosis does not occur as a result of decreased water in the skin, but rather is the result of abnormal keritinization and desquamation. 2

Signs and Symptoms
Although xerosis is most prominent on the lower legs of patients who are middle-aged or older, the condition also commonly presents on the trunk, forearms, and hands. 1,3 Xerosis may occasionally appear on the face, as well.2 Clinically, the skin appears tessellated (mosaic-like) with dull scales and mild erythema.2 The skin also tends to itch and flake, which may be distracting and distressful for some patients.4

Symptoms are usually exacerbated in the winter because of low outdoor humidity due to cold temperature and wind, and low indoor humidity due to central heating systems. 1 The stratum corneum loses excessive water under the condition of low humidity, which dries the surface and makes the skin shiny and less pliable. Once xerosis manifests, the condition tends to wax and wane with the surrounding environmental conditions and persists indefinitely.2

Complications and Differential Diagnosis

Dermatitis may result from the drying effect of soaps, detergents, or other irritants (e.g., alcohol) that are applied to the skin alone or are contained in skin care products.3,4 Dry skin may also fissure (crack). Irritating substances may enter the fissures and excoriations, causing the skin to become red, itchy, swollen, or painful.4 When this occurs, the condition is referred to as eczema craquelé or asteatotic eczema.4 Pharmacists should encourage treatment interventions (table 1) to help patients avoid complications and the possibility of further irritation, friction, and skin breakdown, which may make the skin susceptible to infection.5

The differential diagnosis of xerosis includes atopic eczema, autosomal dominant ichthyosis, nummular eczema, and stasis dermatitis, as outlined in table 2. Inherited ichthyoses, characterized by excessive accumulation of scales on the surface of the skin, are classified according to clinical features such as age at onset (e.g., birth, infancy, or childhood), type of scale (e.g., fine, large and dark, large and coarse, thick and warty), associated clinical findings (e.g., corneal opacities, ectropion, blisters) and genetic features (e.g., autosomal dominant, X-linked, autosomal recessive). In these cases, it is recommended that genetic counseling and treatment guidance be sought through consultation with a dermatologist.3

Very mild autosomal dominant ichthyosis, in the absence of a positive family history, may in fact be difficult to distinguish from xerosis.2 A diagnosis of acquired ichthyosis may be an early manifestation of a systemic disease such as hypothyroidism, lymphoma, leprosy, or AIDS. Fine scales may appear locally on the trunk and legs or may be thick and widespread. Since the diagnosis of xerosis is a clinical one, skin biopsy is usually not diagnostic. However, in sarcoidosis, in which thick scales may be present on the legs, a biopsy usually shows typical granulomas.

Importance of Maintaining Skin Integrity in Seniors
Identifying and addressing xerosis may be viewed as an integral part of maintaining skin integrity. This is especially important in seniors, since aging skin experiences anatomic changes resulting in altered physiologic behavior and susceptibility to disease.6 Specifically, there is a decrease in epidermal renewal, tissue repair, hair and nail growth, and the quantity of eccrine, apocrine, and sebum secretion. As a person ages, a decrease in the inflammatory response, absorption, and cutaneous clearance occurs due to a decrease in cutaneous vascular supply. In fact, a prominent feature of aged skin is the regression and disorganization of small vessels. Additionally, thermal regulation, tactile sensitivity, and pain perception are all impaired to some degree in the aging adult.6 Pharmacists can promote the importance of skin integrity with recommendations regarding cleansing and moisturization of the skin (table 1).

Prophylaxis and Treatment
In general, there is a twofold approach to the treatment of xerosis: (1) minimizing irritation and (2) moisturization.2 Patients should be instructed to limit bathing, especially in soapy baths that strip oil from skin and leave it chapped.2 While some experts recommend bathing once daily in warm water and mild soap, others suggest bathing only every other day and supplementing with sponge baths of the axillae and anogenital areas, since these areas are rarely affected by xerosis.1,2 Patting the skin dry instead of rubbing can also help. Detergents, rubbing alcohol, and skin care products that contain alcohol and other drying agents should be avoided if possible. Irritating materials (e.g., wool) should not be placed next to the skin.1

In general, moisturization through frequent and liberal application of emollients is recommended, especially after bathing when water can be trapped in the skin with an occlusive agent.2 Moisturizers have water-retaining and lubricating properties and exhibit weak antipruritic, anti-inflammatory, antimitotic, and vaso­ constrictive effects, which make them suitable treatments for mildly eczematized xerotic skin.2 The generous and frequent application of moisturizers that contain lanolin or white petrolatum effectively traps and retains water in the skin.4 Scented emollients are not recommended, to avoid skin irritation and contact sensitization.1 Emollients have few side effects, usually confined to contact dermatitis, folliculitis, and miliaria (cutaneous changes associated with retention and discharge of sweat).2

Seniors should be informed that while over-the-counter emollients vary greatly in quality and cost, there is no strict relationship between the two.1 Checking labels for ingredients known to be useful in the treatment of xerosis (table 3) should be encouraged to avoid confusion from misleading claims and advertisements. Some additives in expensive moisturizers, such as collagen and elastin, are used for marketing, not
medical purposes, while other additives, such as vitamin E and fragrances, may provoke an allergic dermatitis.2 An elegant, aesthetically acceptable topical preparation may be advantageous for some patients who may otherwise not adhere to a regimen that requires a thick, greasy ointment (e.g., petrolatum) to be applied under their garments.

Creams and lotions that contain urea or an alpha-hydroxy acid (table 3) are used to hydrate skin, remove scales, and prevent symptoms.1 To increase indoor humidity during the winter, a humidifier may be helpful. Topical cortico­ steroids may be required if the skin becomes temporarily red, swollen, or painful.4 A low-potency topical steroid ointment (e.g., hydrocortisone 1% or 2.5%) is recommended after bathing and at bedtime to treat inflamed, dry skin.1 Since ointments are more potent than creams that contain the same corticosteroid in the same concentration, prolonged use of ointments is discouraged due to systemic absorption.1 It is important to note that topical steroids may actually provoke eczema craquelé in some individuals.2  

The pattern of xerosis has been seen in some drug reactions.7 A drug may have the potential to worsen xerosis by changing the chemical composition of the skin's outer layer. 4 This occurs most classically with those drugs used in the treatment of hypercholesteremia, namely the HMG-CoA reductase inhibitors (statins), which may cause severe xerosis.1,7

In aging skin, anatomic changes result in altered physiologic behavior and susceptibility to disease. Untreated, dry, itching, and scaling xerotic skin can fissure, making a senior susceptible to red, chronically itchy, swollen, or painful skin. Altered bathing habits, avoidance of
irritants, and adequate moisturization are the key treatment modalities for xerosis. Topical steroids may be necessary if more conservative measures fail. Pharmacists can assist by educating seniors about useful product categories. Pharmacists may also appropriately recommend effective treatments that are commensurate with a patient's aesthetic preferences and cost constraints.

1. Beers MH, Berkow R, eds. The Merck Manual of Geriatrics. 3rd ed. Whitehouse Station, NJ: Merck & Co; 2000:1247-1248.
2. Kaplan LA. Xerosis. In: Newcomer VD, Young EM Jr. Geriatric Dermatology: Clinical Diagnosis and Practical Therapy. New York : Igaku-Shoin; 1989:309-314.
3. Beers MH, Berkow R. The Merck Manual of Diagnosis and Therapy. 17th ed. Whitehouse Station, NJ : Merck & Co; 1999:831.
4. Beers MH, Jones TV, Berkwits M, et al, eds. The Merck Manual of Health & Aging. Whitehouse Station, NJ : Merck Research Laboratories; 2004:432-433.
5. Allman RM. Pressure Ulcers. In: Hazzard WR, Blass JP, Halter JB, et al. Principles of Geriatric Medicine and Gerontology. 5th ed.

New York : McGraw-Hill, Inc; 2003:1563-1569.
6. Balin AK. Aging of Human Skin. In: Hazzard WR, Andres R, Bierman EL. Principles of Geriatric Medicine and Gerontology. 2nd ed. New York : McGraw-Hill, Inc.; 1990:383-412.
7. Millikan LE. Drug Eruptions. In: Newcomer VD, Young EM Jr. Geriatric Dermatology: Clinical Diagnosis and Practical Therapy. New York : Igaku-Shoin; 1989:169-177.

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