Xerosis and Pruritus in Elderly Patients, Part 2

    Pruritus is a perceived itching sensation, often psychogenic in origin. Characteristic features of pruritus include scratching and inflammation. The effect of histamine on the touch proprioceptors is thought to induce itching and is mediated exclusively by the peripheral nervous system.¹ Itching evokes the desire to scratch — scratching produces an immunology-based inflammatory, immunologic response.^2-5 The condition is often associated with other underlying diseases.¹

    Pruritic skin diseases are the most common dermatological problem in the elderly.⁶ Many dermatological and metabolic conditions also involve pruritus. Xerosis (a skin condition characterized by dry, cracked, and fissured skin) is the most common underlying condition^6,7;  other conditions include infestations, infection (fungal, bacterial, or viral), lichen planus, nodular prurigo, dermatitis, eczema, and miliaria.⁸ In addition to common skin conditions, pruritogens include drug therapy, psychological causes, and various systemic diseases. Underlying metabolic conditions that can produce pruritus include renal failure, HIV, diabetes mellitus, thyroid disease, parathyroid disease, hypervitaminosis A, iron-deficiency anemia, neuropathy, hepatic disease, malignancy, and drugs. Initial treatment focuses on relieving pruritus before the specific etiology is determined. To maximize effectiveness, pruritus treatment strategy is then tailored to the specific underlying condition. 

Pathology

    The pathophysiology of pruritus is not well understood. Inflammation — a recognized feature of the condition — results from the activation of the body’s immune response, normally to an antigen. The surfaces of involved skin cells contain immunoglobulin E (IgE) molecules whose main physiological role is to trigger acute inflammation,⁴ releasing compounds such as histamine and heparin (vasoactive amines).⁹ Histamine causes small blood vessels to dilate and heparin acts as an anticoagulant. The lymphocyte receptors on skin blood vessel walls aid the migration of lymphocytes from the blood into the tissues,¹⁰ effectively setting the stage for inflammation. Repetitive rubbing, scratching, and touching (foreign body or self-induced) exacerbate inflammation and pigmentary cutaneous manifestations,⁸ which include excoriations, prurigo nodularis, and lichen simplex chronicus.^8,11,12

Clinical Work-Up and Initial Treatment

    Initial treatment focuses on immediate relief of pruritus. The goal is to dull the inflammatory response.¹³ Recommended treatment regimens and products for pruritus are highly variable.⁷ Furthermore, pruritus relief evaluation is subjective; valid itch measurement techniques for the evaluation of antipruritic therapies are needed.² Mild pruritus may respond to nonpharmacologic measures such as avoiding hot water and irritants, maintaining proper humidity, using cool water compresses, trimming the nails, and behavior therapy. Topical symptomatic treatments include moisturizers, emollients, tar compounds, topical corticosteroids, topical anesthetics such as benzocaine and dibucaine, and pramoxine HCl (alone or combined with menthol, petrolatum, or benzyl alcohol).¹⁴

    Once temporary pruritic relief is obtained, the underlying cause should be identified.⁸ This process begins with a thorough history, physical exam, and laboratory result evaluation. Subsequent pruritus therapy aims to optimize treatment efficacy by adapting the treatment to the underlying etiology. For example, doxepin cream has been proven effective in treating pruritus associated with eczematous dermatitis¹³; it can be used alone for acute pruritus or with corticosteroids in chronic conditions.¹⁴ Other treatments include localized ultraviolet B phototherapy and intralesional injections of corticosteroid.¹⁴ Zafirlukast is effective for pruritus associated with atopic dermatitis.¹⁵ Serotonin type 3 (5-HT3) receptor antagonists are useful when treating cholestatic- and uremic-related pruritus.¹⁶ Fluvoxamine is somewhat effective in reducing psychogenic excoriation from scratching.¹⁷ Other medication/measures employed to treat generalized pruritus include odansetron (5-HT3 antagonist) and transcutaneous nerve stimulation.⁸

    In patients with HIV, systemic therapies such as indomethacin and pentoxifylline and nightly administration of hydroxyzine with or without doxepin have proven more beneficial than topical steroids.¹⁴ Danazol has proven a good alternative for patients with severe refractory pruritus associated with myeloproliferative and other systemic disorders.¹⁸ One study¹⁹ of persons on hemodialysis who received either fish oil, olive oil, or safflower oil documented an improved patient perception of pruritus symptoms. Due to the presence of reduced stratum corneum hydration, simple emollient therapy may relieve pruritus in patients on maintenance dialysis.²⁰ Other drug treatments include activated charcoal, antihistamines, capsaicin cream, amitriptyline tablets at night, and cholestyramine.^12,21 Cooling lotions like camphor and menthol have been effectively used.^12,21 Avoiding fragrant soaps, irritating chemicals, and hot water helps reduce pruritus, especially in elderly patients who exhibit the xerotic changes of aging.

Allergic Responses

    Allergic skin disorders in the elderly—which may arise from contact with or ingestion of offending allergens—must be distinguished from other causes of itching in the elderly, such as xerosis, itching due to systemic disease, and bullous disease. Elderly people have decreased cell-mediated immunity and may be more difficult to sensitize under experimental conditions. However, they have had many years to acquire allergic responses; frequently, they develop contact dermatitis.

    Patch testing is an important tool to diagnose contact allergy in the elderly; particular attention should be paid to patients at high risk for contact dermatitis, such as those with chronic lower-extremity dermatitis or ulcers due to venous stasis. Knowledge of common sensitizers is important, especially when prescribing topical medications to high-risk patients. Contact allergy to dressings used to treat stasis ulcers, dental prostheses, and medications used to treat ocular disease are common in the elderly as a result of increased usage and exposure. Allergic noneczematous dermatoses caused by ingested allergens are much more commonly a result of medications than food in the elderly. In particular, urticarial skin reactions often are associated with the administration of antibacterials, nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, or opioids. Systemic reaction to anticonvulsants, gold, allopurinol, or diuretics commonly result in morbilliform rashes. Tetracyclines, diuretics, NSAIDs, and antihyperglycemic agents can cause phototoxic reactions.

    Concurrent use of multiple medications in the elderly can make diagnosis of drug allergy difficult. Diagnosis is most commonly accomplished by observing clinical response to withdrawal of the medication; reaction reduction may not be immediate. Clinical improvement from lichenoid cutaneous reactions, for example, may take several months following withdrawal of the offending drug.²²

Conclusion

    The perceived itch of pruritus induces scratching and subsequent immunologically mediated inflammation. The condition often is associated with several underlying dermatological and systemic diseases but can be psychogenic in origin. Xerosis is the most common underlying dermatological condition. Several infectious, metabolic, hepatic, hematological, and systemic conditions are associated with pruritus. Immediate relief of pruritus is the initial treatment goal; subsequently, a thorough history, physical examination, and laboratory testing work-up is necessary to find the underlying treatable cause. An effective pruritic treatment strategy, including pharmacological choices, should be tailored to the underlying etiology.

    The Skin Matters series is made possible through the support of the Skin Health Division of Coloplast Corp., Marietta, Ga.
    This article was adapted from Norman RA. Xerosis and pruritus in elderly patients, part 2. ECPN. April  2005.

1.   Johansson O, Virtanen M, Hilliges M. Histaminergic nerves demonstrated in the skin. A new direct mode of neurogenic inflammation? Exp Dermatol. 1995;4(2):93–96.

2.    Wahlgren C. Measurement of itch. Semin Dermatol. 1995;14(4):277–284.

3.    Woodward DF, Nieves AL, Spada CS, Williams L, Tuckett R. Characterization of a behavioral model for peripherally evoked itch suggests platelet-activating factor as a potent pruritogen. J Pharmacol Exp Ther. 1995;272(2):758–765.

4.    Seidenari S, Giusti G. Objective assessment of the skin of children affected by atopic dermatitis: a study of pH, capacitance, and TEWL in eczematous and clinically uninvolved skin. Acta Derm Venereol. 1995;75(6):429–433.

5.    Yamaguchi T, Maekawa T, Nishikawa Y, et al. Characterization of itch-associated responses of NC mice with mite-induced chronic dermatitis. J Dermatol Sci. 2001;25(1):20–28.

6.    Thaipisuttikul Y. Pruritic skin diseases in the elderly. J Dermatol. 1998;25(3):153–157.

7.    Fleischer AB Jr. Pruritus in the elderly: management by senior dermatologists. J Am Acad Dermatol. 1993;28(4):603–609.

8.    Leung C. Pruritus. In: Kuen-kong LO, Lai-yin C, Yuk-ming T, eds. Handbook of Dermatology and Venerology: Social Hygiene Handbook, 2nd ed. Western District, Hong Kong: Social Hygiene Service Department of Health; 1997.

9.    Rukwied R, Lischetzki G, McGlone F, Heyer G, Schmelz M. Mast cell mediators other than histamine induce pruritus in atopic dermatitis patients: a dermal microdialysis study. Br J Dermatol. 2000;142(6):1114–1120.

10.    Graham J. A guide to atopic eczema [Honours Project]. Edinburgh, Scotland: Napier University, Department of Biological Sciences, 1997. Available at: http://www.biol.napier.ac.uk/BWS/COURSES/projects/eczema/aeguide.htm. Accessed February 25, 2005.

11.    Kosko DA. Dermatologic manifestations of human immunodeficiency virus disease. Lippincotts Prim Care Pract. 1997;1(1):50–61.

12.    Robertson KE, Mueller BA. Uremic pruritus. Am J Health Syst Pharm. 1996;53(18):2159–2170.

13.    Drake LA, Millikan LE. The antipruritic effect of 5% doxepin cream in patients with eczematous dermatitis: doxepin study group. Arch Dermatol. 1995;131(12):1403–1408.

14.    Herting R Jr. Dermatology: pruritus. In: University of Iowa Family Practice Handbook, 3rd ed. Iowa City, Iowa: University of Iowa; 1997:1–13.

15.    Zabawski EJ Jr, Kahn MA, Gregg LJ. Treatment of atopic dermatitis with zafirlukast [letter]. Dermatol Online J. 1999;5(2):10.

16.    Weisshaar E, Ziethen B, Gollnick H. Can a serotonin type 3 (5-HT3) receptor antagonist reduce experimentally-induced itch? Inflamm Res. 1997;46(10):412–416.

17.    Arnold LM, Mutasim DF, Dwight MM, Lamerson CL, Morris EM, McElroy SL. An open clinical trial of fluvoxamine treatment of psychogenic excoriation.J Clin Psychopharmacol. 1999;19(1):15–18.

18.    Kolodny L, Horstman LL, Sevin BU, Brown H, Ahn YS. Danazol relieves refractory pruritus associated with myeloproliferative disorders and other diseases. Am J Hematol. 1996;51(2):112–116.

19.    Peck LW. Essential fatty acid deficiency in renal failure: can supplements really help? J Am Diet Assoc. 1997;97(10 Suppl 2):S150–S153.

20.    Morton CA, Lafferty M, Hau C, Henderson I, Jones M, Lowe JG. Pruritus and skin hydration during dialysis. Nephrol Dial Transplant. 1996;11(10):2031–2036.

21.    Ngan V. Pruritus (itch). Available at: http://www.dermnetnz.org/systemic/itch.html. Accessed February 25, 2005.

22.    Nedorost ST, Stevens SR. Diagnosis and treatment of allergic skin disorders in the elderly. Drugs Aging. 2001;18(11):827–835.