Moisturizers and Cleansers in the Management of Skin Conditions Caused by Personal Protective Equipment and Frequent Handwashing

Sara Mirali, PhD; Patrick Fleming, MD, MSc, FRCPC, FCDA; Charles W. Lynde, MD, FRCPC, DABD

Disclosures

Skin Therapy Letter. 2021;26(4):9-13. 

In This Article

Moisturizers

Moisturizers are widely used to treat AD and ICD. Moisturizers treat damaged skin by repairing the stratum corneum, increasing hydration, and reducing transepidermal water loss (TEWL). In addition to restoring the skin barrier and relieving symptoms, frequent use of moisturizers can reduce the need for topical steroids.[10] While steroids may reduce inflammation, they can also compromise the skin barrier and increase TEWL.[11]

An effective moisturizer should contain an occlusive barrier, humectants, and emollients (Table 1). Occlusives block TEWL by forming a film on the surface of the skin, while humectants retain moisture by attracting water from the environment and from the dermis. Emollients soften the skin by repairing the stratum corneum's lipid-rich matrix and filling the spaces between desquamating corneocytes.

Treatment with moisturizers is largely based on patient compliance. Consumer preferences must be taken into account as compliance will likely be poor if patients are unsatisfied with the treatment.[12] An ideal moisturizer should be non-irritating, hydrating, cosmetically appealing, pH balanced, and contain ceramides.[10,13,14] Moreover, an ideal moisturizer should be inexpensive and widely available.

Non-irritating

Sensory reactions are a common adverse effect of moisturizers. Sensory reactions consist of burning or stinging sensations without evidence of inflammation.[15] Although urea, lactic acid, and pyrrolidine carboxylic acid (PCA) are clinically effective humectants, they cause irritation in some patients, particularly in those with damaged skin.[12,16,17] In contrast, the humectant glycerin is well-tolerated.[16] Preservatives, such as benzoic acid and sorbic acid, can also cause irritation (Table 2).[12,17]

Fragrances are the most common allergen found in moisturizers and are the most frequent cosmetic cause of allergic contact dermatitis.[18,19] Fragrances can also cause photo contact dermatitis and contact urticaria.[20] Moisturizers should be fragrance-free and fragrance-related allergens, such as benzyl alcohols, essential oils, and biologic additives should also be avoided.[18] dermatitis and contact urticaria.[20] Moisturizers should be fragrance-free and fragrance-related allergens, such as benzyl alcohols, essential oils, and biologic additives should also be avoided.[18]

Moisturizers may contain or be used alongside treatments for acne vulgaris, such as retinoids and benzoyl peroxide. These compounds can disrupt the skin barrier and cause further irritation, particularly if patients recently integrated them into their skincare routine.[21] To prevent maskne, skincare routines should be limited to a pH-balanced gentle non-soap cleanser and mild moisturizer free of irritants. Products with a physiological skin surface pH (4.0–6.0) should be used to reduce inflammation and improve skin barrier function.[22] Changes in skincare routine (i.e., addition of a retinol) should be incorporated with caution because mask occlusion may worsen irritation from new products. Likewise, cosmetic products should not be used as mask occlusion will intensify product delivery to the skin, increasing irritation and maskne.

Hydrating Properties

Moisturizers derive their hydrating properties from humectants that attract water from the dermis and from the external environment. Within the stratum corneum, corneocytes contain natural moisturizing factors (NMF), a humectant mixture derived from amino acids and salts. NMF are made of amino acids produced by the breakdown of the protein FLG, which retains water within the corneocytes and maintains skin hydration.[24] Patients suffering from AD are deficient in FLG, resulting in increased TEWL and impaired skin barrier function.[25] Moisturizers containing FLG breakdown products have been shown to improve barrier function in AD patients.[26]

Commonly used humectants include the FLG breakdown products lactic acid and PCA, as well as urea. Another frequently used humectant is hyaluronic acid, which has been shown to be efficacious in mild-to-moderate AD.[27] If patients are sensitive to these humectants, a moisturizer with glycerin should be considered. Glycerin is an effective humectant that is inexpensive and well-tolerated.[16] Because humectants draw up water from the dermis, they must be used in combination with an occlusive agent to prevent TEWL.[28]

Cosmetically Appealing

Moisturizers are formulated to be non-greasy, non-comedogenic, and smoothing. The consistency of a moisturizer depends on its emulsification. Creams are available as water-in-oil (W/O) or oil-in-water (O/W) emulsions. O/W emulsions are less viscous compared to W/O emulsions, which have an oil content between 15–30%. A higher oil content retains more moisture but increases the greasiness of the product.[15]

New emulsion technologies allow for better delivery of active ingredients. Multivesicular emulsions (MVE®) are multi-lamellar emulsions with a series of concentric spheres containing oil and water. Ingredients are stored within the oil or water phases and layers are released slowly over time. While traditional emulsions release all of their ingredients at once, MVEs® allows for sustained release, increasing the effective duration of the product.[29]

pH Balanced

Normal physiological skin surface pH ranges from 4.0–6.0 but is elevated in AD, ICD, and acne.[30–32] Elevated skin pH can result in inflammation, disrupted stratum corneum cohesion, and impaired skin permeability. Moreover, for individuals with acne-prone skin, high pH moisturizers can interfere with the efficacy of topical acne treatments.[22,33] To improve skin barrier function, moisturizers at physiological skin surface pH (4.0–6.0) should be used, although there is limited clinical evidence directly linking low pH moisturizers and reduced irritation.

Ceramide Content

The stratum corneum's lipid-rich matrix is composed of approximately 50% ceramides, 25% cholesterol, and 10–20% fatty acids.[34] Ceramides are synthesized in keratinocytes and play an important role in skin barrier maintenance, cell adhesion, and epidermal differentiation. Reductions in ceramide correlate with clinical irritation and barrier disruption.[35] Natural ceramides are expensive to synthesize but moisturizers containing synthetic ceramides have been shown to reduce symptoms and improve quality of life in patients with AD and ICD.[10,13,14,36]

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