D

ry skin is known as xerosis. The common dermatological skin condition is characterized by pruritic, dry, cracked, and fissured skin with scaling. Xerosis occurs most often on the legs of elderly patients but may be present on the hands and trunk. Xerotic skin looks like a pattern of cracked porcelain. These cracks or fissures are caused by epidermal water loss. The skin splits and cracks deeply enough to disrupt dermal capillaries, and bleeding fissures may occur. Pruritis, or itching, occurs, leading to secondary lesions.
       Scratching and rubbing activities produce excoriation, an inflammatory response, lichen simplex chronicus (leather-like skin), and even edematous patches.¹ Subsequently, environmental allergens and pathogens can easily penetrate the skin, increasing the risk of allergic and irritant contact dermatitis as well as infection. Allergic and irritant contact dermatitis may be a cause for a persistent and possibly more extensive dermatitis, despite therapy.¹ Eczematous changes can occur with a delayed hypersensitivity response, even in advanced age.² Secondary infection is an inherent risk with any break in the skin barrier.

Research

       I recently completed a study of the nursing home patients I treat and found that the 2 most common problems are overwhelmingly xerosis and pruritus (see Table 1). Given these results, this article will focus on the recognition and treatment of xerosis, and Part 2 (which will appear in the April issue of ECPN) will focus on pruritus. Of ultimate importance is the comprehensive treatment of these problems to prevent stasis dermatitis and ulcer formation.

Table 1

Prevalence and Predisposing Factors

       Xerosis affects the elderly, primarily because they have decreased sebaceous and sweat gland activity. This reduced activity predisposes the skin of elderly patients to moisture depletion. There are a number of situations that deplete the skin’s moisture. For example, xerosis tends to relapse in the winter when a lower humidity environment predominates.³ Another situation involves the daily use of cleansers and/or bathing without replacing natural skin emollients.⁴ Additionally, pre-existing disease states, therapies, and medications leave the elderly patient more susceptible to xerosis. Some of these pre-existing situations include radiation, end-stage renal disease, nutritional deficiency (especially zinc and essential fatty acids), thyroid disease, and neurological disorders with decreased sweating, anti-androgen medications, diuretic therapy, human immunodeficiency virus, and malignancies.^5–7

Pathology

       In healthy skin, skin cells called corneocytes detach from neighboring cells, and younger cells from the deeper layers replace them. This orderly process, called desquamation, leads to corneocyte or skin cell loss from the skin surface. Desquamation is controlled primarily by 2 intercellular components called corneodesmosomes and lipids. The intercellular actions of these components provide for the maintenance of tissue thickness. Corneodesmosomes bind the corneocytes to maintain intercellular cohesion and tissue integrity. Effective desquamation requires that corneodesmosomes must eventually be broken down. This process is called corneodesmolysis.
       In healthy skin, corneodesmolysis is totally effective in eliminating the corneodesmosomes.³ This is not the case with xerotic skin. Corneodesmosomes persist and disturb the orderly desquamation process. In chronic and acute dry skin conditions, this disturbed process is manifested by the formation of visible, powdery flakes on the skin surface.⁸
       Another important consideration is that free water is necessary to control the corneodesmolysis process. Adequate lipid content is required to retain the free water. Inadequately hydrated skin cannot provide this free water. Therefore, deficits in both skin hydration and lipid content play a key role in xerosis.³ Consequently, the skin’s inability to retain moisture and provide an effective barrier directly impacts the development of xerosis in aged skin.^9,10

Treatment

       Once the stage is set for xerosis development, the scenarios of flaking, fissuring, inflammation, dermatitis, and infection develop. The vicious xerotic cycle must be broken to disable the process and prevent complications.^11,12 This is precisely the goal of xerosis treatment—break the xerotic cycle.
       To achieve this goal, keratolytics, moisturizers, and steroids are the primary components of xerosis treatment. The keratolytic effect of ammonium lactate 12% lotion is effective in reducing the severity of xerosis. Several studies have demonstrated this benefit.^13,14 Individuals with sensitive skin may not tolerate some products formulated with alpha-hydroxy acids (AHAs) due to unacceptable levels of stinging and irritation. In this case, a sensitive skin variant formulation should be substituted.¹⁵ Liberal use of moisturizers reduces scaling and enhances the corneodesmosome degradation process.^16–18 Additional treatment via application of topical steroids (class 3–6) is recommended in moderate to severe cases.⁴ Antipruritics should be added if severe pruritis is present.¹²
Other additional management suggestions include the following:
• Reduced frequency of bathing with lukewarm (not hot) water
• Minimal use of a nonirritant soap, such as Cetaphil® soap, Oil of Olay®, and Dove®
• Avoidance of harsh skin cleansers
• Application of a moisturizer, such as Theraseal®, directly on skin that is still damp
• Avoidance of friction from washcloths, rough clothing, and abrasives
• Use of air humidification in dry environments.^4,19

Conclusion

       Aged skin is very susceptible to the development of xerosis. The pathophysiology of xerosis is related to abnormal keratin production; elderly have decreased skin fatty acids, which results in decreased skin barrier and hydration. The vicious cycle of the xerotic process makes elderly patients easy targets for xerosis-related complications. The treatment goal focuses on breaking the xerotic cycle to prevent secondary complications.

       Editor’s note: The April issue of ECPN will examine a related skin condition, pruritus (a perceived itching sensation).
       Robert A. Norman, DO, MPH, is a Clinical Associate Instructor in the Department of Internal Medicine, Division of Dermatology, at Nova Southeastern Medical School in Fort Lauderdale, Fla. Dr. Norman is also in private practice in Tampa, Fla.