Tolerance of Fragranced and Fragrance-Free Facial Cleansers in Adults With Clinically Sensitive Skin

For thousands of years, humans have used fragrances to change or affect their mood and enhance an “aura of beauty.”¹ Fragrance is a primary driver in consumer choice and purchasing decisions, especially when considering personal care products.² In addition to fragrance, consumers choose cleanser products based on compatibility with skin, cleansing properties, and sensory attributes such as viscosity and foaming.^3,4 However, fragrance sensitivity is among the most common causes of allergic contact dermatitis from cosmetics and personal care products,⁵ and estimates of the prevalence of fragrance sensitivity range from 1.8% to 4.2%.⁶

A panel of 26 fragrance ingredients that frequently induce contact dermatitis in sensitive individuals has been identified.⁷ Since 2003, regulatory authorities in the European Union require these compounds to be listed on the labels of consumer products to protect presensitized consumers.^7,8 However, manufacturers of cosmetics are not required to specify allergenic fragrance ingredients outside the European Union, and therefore it is difficult for consumers in the United States to avoid fragrance allergens.

Creation of a fragranced product for 
fragrance-sensitive individuals begins with careful selection of ingredients and extensive formulation testing and evaluation. This process usually is followed by testing in normal individuals to confirm that the fragranced product is well accepted and then evaluation is done in clinically confirmed fragrance-sensitive patients and those with a compromised skin barrier from atopic dermatitis, rosacea, or eczema.

Sensitive skin may be due to increased immune responsiveness, altered neurosensory input, and/or decreased skin barrier function, and presents a complex challenge for dermatologists.⁹ Subjective perceptions of sensitive skin include stinging, burning, pruritus, and tightness following product application. Clinically sensitive skin is defined by the presence of erythema, stratum corneum desquamation, papules, pustules, wheals, vesicles, bullae, and/or erosions.⁹ Although some of these symptoms may be observed immediately, others may be delayed by minutes, hours, or days following the use of an irritating product. Patients who present with subjective symptoms of sensitive skin may or may not show objective symptoms.

Gentle skin cleansing is particularly important for patients with compromised skin barrier integrity, such as those with acne, atopic dermatitis, eczema, or rosacea. Standard alkaline surfactants in skin cleansers help to remove dirt and oily soil and produce lather but can impair the skin barrier function and facilitate development of irritation.^10-13 The tolerability of a cleanser is influenced by its pH, the type and amount of surfactant ingredients, the presence of moisturizing agents, and the amount of residue left on the skin after washing.^11,12 Mild cleansers have been developed for patients with sensitive skin conditions and are expected to provide cleansing benefits without negatively affecting the hydration and viscoelastic properties of skin.¹¹ Mild cleansers interact minimally with skin proteins and lipids because they usually contain nonionic synthetic surfactant mixtures; they also have a pH value close to the slightly acidic pH of normal skin, contain moisturizing agents,^11,14,15 and usually produce less foam.^10,16 In patients with sensitive skin, mild and fragrance-free cleansers often are recommended.^17,18 Because fragrances often affect consumers’ perception of product performance¹⁹ and enhance the cleaning experience of the user, consumer compliance with clinical recommendations to use fragrance-free cleansers often is poor.

Low–molecular-weight, water-soluble, hydrophobically modified polymers (HMPs) have been used to create gentle foaming cleansers with reduced impact on the skin barrier.^12,16,20 In the presence of HMPs, surfactants assemble into larger, more stable polymer-surfactant structures that are less likely to penetrate the skin.¹⁶ Hydrophobically modified polymers can potentially reduce skin irritation by lowering the concentration of free micelles in solution. Additionally, both HMPs and HMP-surfactant complexes stabilize newly formed 
air-water interfaces, leading to thicker, denser, and longer-lasting foams.¹⁶ A gentle, fragrance-free, foaming liquid facial test cleanser with HMPs has been shown to be well tolerated in women with sensitive skin.²⁰

This report describes 2 studies of a new mild, 
HMP-containing, foaming facial cleanser with a 
fragrance that was free of common allergens and irritating essential oils in patients with sensitive skin. Study 1 was designed to evaluate the tolerance and acceptability of 2 variations of the HMP-containing cleanser—one fragrance free and the other with 
fragrance—in a small sample of healthy adults with clinically diagnosed fragrance-sensitive skin. Study 2 was a large, 2-center study of the tolerability and effectiveness of the fragranced HMP-containing cleanser compared with a benchmark dermatologist-recommended, gentle, fragrance-free, nonfoaming cleanser in women with clinically diagnosed sensitive skin.

Methods

Study 1 Design

The primary objective of this prospective, randomized, single-center, crossover study was to evaluate the tolerability of fragranced versus fragrance-free formulations of a mild, HMP-containing liquid facial cleanser in healthy male and female adults with Fitzpatrick skin types I to IV who were clinically diagnosed as having fragrance sensitivity. Fragrance sensitivity was defined as a history of positive reactions to a fragrance mixture of 8 components (fragrance mixture I) and/or a fragrance mixture of 14 fragrances (fragrance mixture II) that included balsam of Peru (Myroxylonpereirae), geraniol, jasmine oil, and oakmoss.⁵ All participants provided written informed consent prior to enrolling in the study, and both the study protocol and informed consent agreement were approved by an institutional review board.