Therapeutic Moisturizers in Eczema and Xerosis Management

Anil Kurian, MN¹ and Benjamin Barankin, MD, FRCPC²
1. McMaster University, Hamilton, ON, Canada
2. Toronto Dermatology Centre, Toronto, ON, Canada

Introduction

Eczema is a chronic relapsing dermatitis and, as such, it is imperative to maintain the hydration and barrier function of the skin in these patients with daily moisturizer use. Emollients have long been used to maintain the skin barrier function in patients with eczema (atopic dermatitis). Ceramide and urea-based moisturizers have been shown to be beneficial in reducing transepidermal water loss (TEWL), improving barrier function, and maintaining hydration of the stratum corneum layer of the epidermis; thus, they should be considered a mainstay of treatment in patients with xerosis (dry skin) and eczema.

Overview of Eczema

Eczema is a chronic, pruritic, inflammatory skin disease with wide ranging severity; it is usually the first manifestation of atopic disease. Eczema is a major public health problem worldwide that commonly presents during early infancy and childhood, but can persist or start in adulthood (prevalence in children is 10-20% and 1-3% in adults).¹ Prevalence has increased by two to threefold during the past 30 years in urban areas and industrialized countries, but it remains much lower in rural and less industrialized regions.²

• The causes of eczema are not completely understood, but dysfunction of the skin barrier, likely the result of both genetic and environmental factors, and immune dysregulation are important in its pathophysiology.³
• Acute eczema presents as erythematous patches, papules, plaques, and excoriations secondary to scratching; there may also be weeping of serous exudate. Chronic lesions have the same characteristics, with the addition of lichenification, fissures, and occasional alopecia.⁴
• Partly due to ease of accessibility for scratching, infantile eczema predominantly involves extensor surfaces of the arms and legs, face, and trunk. Scaling, exudate, and fissures are also common findings in infants.
• In adults, flexural areas, face and neck, wrists, and the dorsal areas of the hands and feet are the most commonly affected regions.

Treatment Rationale

The major goal of disease management is to reduce the frequency and severity of flares, and prolong periods of remission. Comprehensive long-term management addresses both skin barrier dysfunction and immune dysregulation, but also includes patient and caregiver education, flare prevention through trigger avoidance and hydration, as well as pharmacologic and non-pharmacologic therapies.³

• Non-pharmacologic patient-specific strategies include removal of allergens (e.g., foods, pet dander, pollen), identification of trigger factors (e.g., stress, low humidity), and a balanced intake of dietary nutrients.⁵
• Particularly during infancy, a higher intake of vitamin A may reduce the incidence of eczema seen in children with a positive family history of atopy. The use of Lactobacillus during pregnancy and while nursing may postpone the onset of eczema in infants and children.⁵
• Pharmacologic therapy includes the use of emollients, topical corticosteroids, and topical calcineurin inhibitors.
• For mild eczema, over-the-counter (OTC) emollients and topical corticosteroids, e.g., hydrocortisone 0.5% (low potency) and clobetasone 0.05% (mid potency) are available for self-treatment.
• Pharmacists are increasingly educating patients and caregivers on safely self-treating and recommending when it is appropriate to seek help from a physician.
• The goals of self-treatment are to stop the itch-scratch cycle, maintain skin hydration, and avoid or minimize factors that can trigger or aggravate eczema.
• An ideal moisturizer is one that performs four functions:⁶
  • repair the skin barrier,
  • maintain skin integrity and appearance,
  • reduce transepidermal water loss (TEWL),
  • restore the lipid barrier's ability to attract, hold, and redistribute water.
• It is appropriate for patients or caregivers to consult a physician if OTC treatments are not providing adequate relief, eczematous lesions appear to be infected, or the patient’s sleep is frequently disturbed by pruritus.⁵

Available Formulations of Therapeutic Moisturizers

Ceramide-based Moisturizers

• Recent biochemical findings indicate that disturbances of epidermal lipid compartment structures (particularly of ceramides) account for the defects in barrier function of atopic dry skin.⁷
• Optimal barrier function requires the presence of sufficient extracellular lipids to form a competent lamellar bilayer system of the stratum corneum.⁷
• Ceramides, which consist of different sub-fractions of lipids, represent one of the major lipid constituents of the extracellular lipids and are functionally important for the stability of the multilamellar bilayer system.
• Studies have revealed that ceramides are reduced in the whole atopic population, but particularly in those individuals in an active phase of the disease.⁸
• A reduction of ceramides has been inversely correlated with TEWL, which can result in chronically dry skin.
• Topical ceramide supplementation controls ceramide deficiency and improves the overall skin condition.⁶
• Their benefits are derived from prophylactic and regular use, which may reduce the need for topical corticosteroids and calcineurin inhibitors, and possibly mitigate the side effects from these medications.
• OTC ceramide-based moisturizers include Impruv® cream and Cetaphil Restoradermâ"¢ lotion. CeraVeâ"¢ and TriCeram® are available in the U.S. only.

Prescription Ceramide-based Moisturizers

• These consist of a higher percentage (compared to OTC brands) combination of ceramides, cholesterol, and fatty acids that mimic those naturally found in the skin.⁹
• EpiCeram® was approved by Health Canada in September 2009 as a Class 2 medical device for use as a non-steroidal lipid barrier emulsion to manage burning and itching symptoms associated with dry skin conditions, such as eczema.
  • In a study involving 113 children with moderate to severe atopic dermatitis, similar efficacy to a midstrength topical corticosteroid was demonstrated.⁹
  • This multi-lipid emulsion has a favourable safety profile and does not appear to have substantial restrictions for use, such as treatment duration or patient age.
• Prescription ceramide-dominant formulations include EpiCeram® cream (available in Canada and the U.S.) and Atopiclair® and MimyX® (available in the U.S. only).

Urea-containing Moisturizers without Hydrocortisone

• Urea-based moisturizers are OTC formulations that are indicated for xerotic skin with or without pruritus.
• Urea works by enhancing the water-binding capacity of the stratum corneum and long-term treatment with urea has been demonstrated to decrease TEWL.¹⁰
• Application of these moisturizers is recommended shortly after bathing, while the skin is still wet.
• The short-term therapeutic effects of urea-based moisturizers are apparent in patients even after 1 week of daily application in those with dry skin and eczema.¹¹
• It has also been shown that long-term urea application reduces the susceptibility to skin irritation from sodium lauryl sulfate, a surfactant commonly used in many soaps, shampoos, detergents, and toothpastes.
• The protective effect (after prolonged application) of urea-containing moisturizers has promising clinical ramifications, such as reduction of contact dermatitis from irritating stimuli.¹⁰
• Higher concentration urea-based formulations induce more prominent keratolytic (softening/shedding) activity that can increase skin irritation. A lower concentration is generally used on the face and body, whereas a higher concentration may be applied to thickened skin areas (e.g., feet).
• OTC urea-based moisturizers include various strengths of urea: 5% (e.g., Eucerin® cream); 10% (e.g., Uremol® 10 cream or lotion, Eucerin® lotion or cream, Urisecâ"¢ cream); 12% (e.g., Uresecâ"¢ lotion); 20% (e.g., Uremol® 20 cream); 22% and 40% urea creams.
• Urea 40% cream is a potent keratolytic that is not suitable for use as a regular moisturizer.

Urea-containing Moisturizers with Hydrocortisone

• Urea-based moisturizers with hydrocortisone are prescription strength formulations and are effective for xerotic skin with inflammation and mild eczema.⁴
• Topical corticosteroids are effectively used for controlling active skin inflammation in eczema. The lowest effective potency of topical corticosteroids is always preferred for the local treatment of lesions.
• Combining an emollient with a corticosteroid has been shown to be effective. A cohort study found that the addition of 10% urea to a commercially prepared steroid cream gave better results in treating subacute atopic eczema than the steroid cream alone.¹²
• Side-effects from topical steroids are directly related to the potency of the compound and the length of use.
• Potential risks from long-term topical steroid use include fungal infections, impetigo, viral warts, and herpes simplex. As well, discontinuation of topical corticosteroids may lead to a flare of symptoms.
• Low-potency hydrocortisone 1% cream has been found to be quite safe for cutaneous use.
• Prescription-based urea moisturizers containing 10% urea with 1% hydrocortisone are available in lotion or cream preparations (e.g., Uremol® HC).

Diabetic Skin Care Management

• Xerosis of the feet is a common skin condition; incidence increases with age, exposure to dry winter conditions, and physiological changes that alter circulatory supply to the lower extremities (e.g., diabetes).
• People with diabetes have a high incidence of xerosis of the feet, especially on the heels.
• While assessing for predictors of foot lesions in diabetic patients, one study found that 82.1% of this cohort had skin with dryness, cracks, or fissures.11 An unpublished survey of 105 consecutive patients with diabetes conducted by one of the authors revealed that 75% had clinical manifestations of dry skin.
• Dry skin often leads to cracks and fissures that can act as portals of entry for bacteria. These cracks and fissures are associated with an increased risk of cellulitis and foot ulceration that, if left unchecked, can eventually lead to amputation.
• Xerosis of the feet in diabetic individuals can be controlled with the regimented use of moisturizers.¹¹
• Healthcare providers should routinely inspect the feet of diabetic patients and encourage daily moisturization.
• Urea has been found to be a potent skin humidifier (by decreasing TEWL) and descaling agent.
• Studies of diabetic patients revealed that urea is safe and effective in controlling xerosis of the feet and showed longer-lasting effect than other emollient creams.¹¹
• Urea cream (especially at 40% strength) works as a keratinolytic and helps in the treatment of corns and calluses of the feet.¹³ This can be functionally important as these hyperkeratotic papules can be uncomfortable, and even painful, thereby restricting physical activity in affected individuals.

Conclusion

References

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6. Anderson PC, et al. Curr Opin Pediatr 21(4):486-90 (2009 Aug).
7. Chamlin SL, et al. J Am Acad Dermatol 47(2):198-208 (2002 Aug).
8. Di Nardo A. Acta Derm Venereol 78(1):27-30 (1998 Jan).
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11. Trung H, et al. Ostomy Wound Manage 48(5):30-6 (2002 May).
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13. Hogan DJ, et al. Corns: treatment and medication. Available at: http://emedicine.medscape.com/article/1089807-treatment. Accessed: September 30, 2010.
14. Loden M. J Eur Acad Dermatol Venereol 19(6):672-88 (2005 Nov).

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