COSMETIC CONSULTATION Optimizing Topical Axillary Perspiration Control Zoe Diana Draelos, MD ontrolling axillary perspiration can be a chal- clothing. The need to develop a topical antiperspirant lenge for dermatologists. When perspiration is that controls sweat yet is compatible with skin and C related to anxiety, the challenge is even greater. clothing has led to all of the currently marketed prod- Who would have thought that our armpits could be ucts. This article takes a critical look at topical axillary a mirror of our inner state of repose? While there are perspiration control. many methods for controlling perspiration with oral medications and injectable neurotoxins, the product Antiperspirants vs Deodorants most commonly used to control axillary sweating is topi- The words antiperspirant and deodorant are sometimes cal antiperspirant. A casual evaluation of the contents of used interchangeably in the common vernacular, but to US Transportation Security Administration–approved the cosmetic chemist these are 2 very different personal carry-on bags of liquids revealed that every bag contained care products. Antiperspirants contain ingredients to a topical antiperspirant of some type. From a sales per- decrease sweating, while deodorants are used solely to spective, topical antiperspirants are a big-volume busi- manage axillary odor. For this reason, all antiperspirants ness in the United States andCOS usually occupy a half isleDERM can be considered deodorants, but not all deodorants are display in mass merchandisers, such as Target, Walmart, antiperspirants. Table 1 lists the mechanisms for axillary and Walgreens. odor control. Most products currently on the market are Topical antiperspirants are available in a variety of both antiperspirants and deodorants. formulations such as stick, cream, gel, and aerosol spray yet the active ingredientDo is an aluminum-containing Not Perspiration Copy and Axillary Odor compound in each of them. The health safety of topical Perspiration is the perfect medium for bacterial growth, antiperspirants has been debated for years. Most recently, which accounts for the axillary odor associated with topical antiperspirants have been linked to breast can- sweating. Axillary odor is caused by the action of bacteria cer in the media but no medical relationship has been on sterile apocrine and eccrine sweat. Apocrine sweat is established. While topical antiperspirants are not to be responsible for a large part of the odor because it is rich worn during breast mammography examinations, the in organic materials. Eccrine sweat, on the other hand, restriction is not related to breast cancer. The US Food is more dilute and does not provide a high concentra- and Drug Administration expressed some concern in tion of nutrients for bacterial growth. However, eccrine 1978 regarding the long-term inhalation risk of aerosol sweat indirectly promotes axillary odor by dispersing antiperspirants; however, these preparations remain on apocrine sweat over a larger area and providing the the market. moisture necessary for bacterial growth. Axillary hair also The first antiperspirant, composed of a 25% solution contributes to odor by acting as a site for apocrine secre- of aluminum chloride hexahydrate in distilled water, tions to collect and increases the surface area suitable for was introduced in 1916. This highly effective formula- bacterial proliferation. tion only required application every other day but was Deodorants function either by masking the axillary odor extremely irritating and the low pH level damaged with a perfume or decreasing axillary bacteria growth. Therefore, many deodorants contain antibacterials, such as Dr. Draelos is Consulting Professor, Department of Dermatology, quaternary ammonium compounds (benzethonium chlo- Duke University School of Medicine, Durham, North Carolina. ride) and cationic compounds (chlorhexidine, triclosan). The author reports no conflict of interest in relation to this article. Mechanism for Perspiration Control Correspondence: Zoe Diana Draelos, MD (zdraelos@ Topical antiperspirants reduce axillary moisture by northstate.net). employing aluminum salts to create a plug within the 110 Cosmetic Dermatology® •MARCH 2010 • Vol. 23 No. 3 Copyright Cosmetic Dermatology 2010. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. COSMETIC CONSULTATION TABLE 1 TABLE 2 Mechanisms for Axillary Efficacy of Topical Odor Reduction Antiperspirant Formulations Reduce apocrine gland secretions Formulation Sweat Reduction, % Reduce eccrine gland secretions Aerosol 20–33 Remove apocrine and eccrine gland secretions from Cream 35–47 the axilla Liquid 15–54 Decrease axillary bacterial colonization Lotion 28–62 acrosyringium to occlude apocrine and eccrine ducts. Roll-on 14–70 Sometimes the aluminum is combined with zirconium Stick 35–40 to enhance efficacy. It takes about 10 days to create the plug, which physically blocks the transport of sweat from the gland onto the skin surface. Conversely, it takes products. These products have a slightly higher con- 14 days for the plug to dissolve. It is for this reason that centration of active ingredient that must reduce sweat the best results with topical antiperspirants are achieved by 30% to substantiate the highly effective claim on the with daily use to maintain theCOS acrosyringeal plug. DERMpackage labeling, but also are recommended for twice- In order for the antiperspirant to work it must physi- daily use. Twice-daily use is actually the key to their cally contact every sweat duct. Even and thorough appli- enhanced efficacy. The antiperspirant must remain in the cation to the entire axillary vault is necessary for optimal axillary vault long enough to form or maintain the plug in results. Some topical antiperspirants have a grid to the acrosyringium. If heavy sweating occurs during appli- encourage even applicationDo and metered dosingNot adminis- cation, Copy the antiperspirant is washed away and rendered tered through turning a knob at the bottom of the appli- ineffective. Because the armpit is generally at rest at night, cator. Using the amount of antiperspirant recommended bedtime application of topical antiperspirants allows the on the package label is important. ingredients to contact the skin longer and create a better acrosyringeal plug that translates into enhanced efficacy. Antiperspirant Efficacy Increased efficacy can be achieved with any topical anti- An efficacious antiperspirant must reduce axillary sweat- perspirant that is used both morning and evening. ing by at least 20%. The degree of sweat reduction is The most effective antiperspirants create a deep plug in determined partly by the formulation. Table 2 lists the the acrosyringium. The more superficial the acrosyringeal efficacy of a variety of currently marketed formula- plug the less sweat control is obtained. Unfortunately, tions. Notice that the efficacy range is broad but overall there is a direct connection between skin irritation and aerosols are the least effective and roll-ons are the most acrosyringeal plug depth. Efficacious formulations must effective. This is due to the ability of the product to address both issues to create a skin-friendly product. contact all of the sweat ducts in the axilla to deliver an Some manufacturers include skin-protecting ingredients, optimal dose. such as dimethicone in topical antiperspirant formula- Antiperspirants are considered over-the-counter drugs tions to increase efficacy while counteracting the inherent and thus must follow the rules set forth in the mono- possibility of irritant contact dermatitis. graph covering their formulation. The types of materials that can be incorporated in antiperspirants and their Antiperspirant Failure concentration are carefully controlled by the US Food Antiperspirants can and do fail to meet patient expecta- and Drug Administration. This accounts for the similarity tions for sweat control. As a matter of fact, most of the in formulation by a variety of manufacturers. patients who seek out the help of a dermatologist for the A new category of topical antiperspirants that have purpose of discussing sweat control are antiperspirant been introduced are labeled as “clinical strength” failures. There are a few easy tips that the dermatologist Vol. 23 No. 3 • MARCH 2010 • Cosmetic Dermatology® 111 Copyright Cosmetic Dermatology 2010. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. COSMETIC CONSULTATION might wish to share with patients in need of assistance in you don’t use it, it doesn’t work. Individuals who apply controlling perspiration: topical antiperspirant sporadically will not experience 1. Apply topical antiperspirants to dry armpits—The optimal sweat control. Daily application is necessary for antiperspirant must remain in physical contact with the efficacy, and twice-daily application is even better as pre- acrosyringium long enough to create a plug. If the anti- viously discussed. Consecutive application for 10 days is perspirant is applied to a wet armpit, either wet from necessary to determine the optimal benefit that can be showering or from perspiration, it will be diluted and achieved from a given antiperspirant formulation. not as effective. The armpit can be dried with a hair dryer before antiperspirant application if necessary. Summary 2. Do not shave aggressively—Plugs created in the acro- Topical antiperspirants