Dermatology Online Journal

Common Misconceptions in Contact Dermatitis Counseling
Rajani Katta MD
Dermatology Online Journal 14 (4): 2

Associate Professor of Dermatology, Director, Contact Dermatitis Clinic, Baylor College of Medicine, Houston, TX.

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Abstract

Both physicians and patients hold many misconceptions when it comes to allergen avoidance. Ten commonly held misconceptions are exposed, allowing more accurate approach to the individual with cutaneous allergies.

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Introduction

Patients with sensitive skin, eczema, or a history of cutaneous hypersensitivity are often desperate for products that will soothe or heal inflammation of the skin. Such individuals are confronted with shelves of products at their local drugstore, many claiming to be "hypoallergenic," "safe for sensitive skin," "gentle on baby's skin," or "formulated for patients with eczema." Patients who head to the Internet and seek similar products are faced with an even more bewildering array of choices. Most of these labels do not have clear-cut definitions, and patients with contact dermatitis can not rely on such terms to rationally direct product choice. Similar difficulties arise with other commercial products and their description. Both physicians and consumers may hold inherent misconceptions about the best ways to avoid allergens and choose "safe" products.

Allergic contact dermatitis (ACD) may be seen either as a primary diagnosis or as a secondary factor exacerbating or interfering with the therapy of chronic eczematous states. Clinically, the diagnosis would seem to be straightforward. In ACD, a person comes into contact with an allergen, such as poison ivy. Approximately 48 hours later the individual develops a rash at the site of contact. From a scientific standpoint, ACD represents a straightforward, well-defined immunologic event, namely a Type-IV T-cell mediated delayed-type hypersensitivity.

However, a number of factors conspire to make the diagnosis and therapy of ACD more complex. Avoidance of all known allergens is the mainstay of treatment. However, physicians who provide counseling on allergen avoidance will find that this is not as easy as it initially appears. Misconceptions regarding product choices and their accompanying terms and labels abound. In this article, I emphasize ten truisms, points of major importance when educating patients on allergen avoidance and points which help clarify areas of misconception.

All-natural does not equate to safer

This misconception demonstrates the power of marketing. Even a cursory review of drugstore shelves discloses many products termed all-natural therapy and often touted as calming creams or for eczema care. In recent years, many patients seem to be turning to such all-natural products in an effort to avoid the chemicals that they perceive are worsening a dermatitis. In reality, most patients need to be specifically admonished that all-natural does not equate to safe (or even safer).

One allergen of major significance is balsam of Peru, which would be considered a natural substance. Balsam of Peru is an aromatic fluid obtained by cutting the bark of the tree Myroxolon balsamum. It and its constituents are used commonly as fragrance and flavoring agents. In a study analyzing data from the North American Contact Dermatitis Group (NACDG), after accounting for both the proportion of the population allergic to the allergen and the likelihood of relevance to the patient's complaint, the investigators found that fragrance mix ranked highest of all the allergens tested. Balsam of Peru was ranked third [1].

There are a number of other natural products such as botanical extracts and essential oils that can serve as fragrance allergens or as allergens in their own right. An Internet search reveals innumerable products marketed for those with sensitive skin that utilize such substances. Oak moss absolute, geraniol, ylang-ylang oil, and sandalwood oil, while considered natural, are important allergens. This point must be emphasized to patients. As we should all recall, poison ivy is all natural.

Direct contact is not necessary in ACD

Have you ever heard this query, "I don't use anything at all on my eyelids. Why are they still breaking out?" Many women with eyelid dermatitis will stop wearing eye makeup under the assumption that that should solve the problem. However, direct contact is not necessary for ACD. There are numerous examples of transfer contact dermatitis, in which transfer of the allergen to a distant site leads to dermatitis. Patients do not usually think of these scenarios, and dermatologists must be alert to suspect and then detect such allergens.

Transfer can occur in many different ways. In consort dermatitis, a patient may react to the spouse's use of a product, as in the wife who develops facial dermatitis from her husband's aftershave. A child may develop poison ivy dermatitis from hugging the dog who was rolling outdoors. A significant historical cause of eyelid dermatitis was allergy to tosylamide formaldehyde resin, found in nail polish. Although applied to the nails, many patients exhibit dermatitis on the face, eyelids, or neck. This resin is no longer used as commonly today, although it remains in some Sally Hansen Hard as Nails® polishes and in some OPI nail polish a brand frequently used in nail salons.

Hair care products are another covert source of allergens in eyelid dermatitis. Patients may react to shampoo ingredients that briefly contact the eyelids in the shower, or may react to ingredients in hair gel that are transferred to the pillow and then the face. Jewelry or other metallic objects may cause eyelid dermatitis as well. Gold jewelry is an often unsuspected cause of eyelid dermatitis [2]. Nickel is another potential cause, as sweat can leach nickel from metallic objects. Rietschel and Fowler in the textbook Fisher's Contact Dermatitis describe how "wandering, perspiring fingers may convey nickel in solution from metallic objects to distant sites" [3].

The term hypoallergenic on a label has almost no meaning

Manufacturers may put the term hypoallergenic on a label to suggest that these products are gentler, are less likely to cause allergic reactions, and are safer for those with sensitive skin. However, there are neither concrete federal standards nor unequivocal definitions that govern the use of the term hypoallergenic. Moreover, manufacturers are "not required to submit substantiation of hypoallergenicity claims to FDA" [4]. Therefore, this term has no meaning, and its presence on a product label should not impact a patient's choice of skin care products.

The term fragrance-free does not equate to free of fragrance allergens

Avoiding fragrance in skin care products is a much more daunting task than one might suspect. Although patients associate fragrance mainly with perfume or cologne, fragrance is ubiquitous, and is added to most of the personal care products sold in the United States. Any product that contains fragrance usually contains a mix of several different ingredients. However, individual fragrance ingredients are considered proprietary information. Therefore, the label need only indicate "fragrance," "perfume," or "parfum." Also, some ingredients that serve as fragrance allergens may not easily be recognized as such. This includes ingredients such as benzaldehyde and benzyl alcohol. Making the task even more complex is that "fragrance-free" does not equate to "free of fragrance allergens." Many dermatologists recognize that unscented products often contain masking fragrance. However, even fragrance-free products may legally contain fragrance allergens. If the manufacturer states that a fragrance allergen is used in a product "to serve another purpose," then it may legally carry the label of fragrance-free. Some fragrance allergens serve as preservatives, and some fragrant botanical extracts may serve as moisturizers. A review of popular brands and products reveals that many fall into these categories [5].

Parabens are not a major cause of skin allergy

Patients with dermatitis may present with concerns about parabens in their cosmetics and personal care products. Some may have already switched to paraben-free products. Manufacturers have provided a number of paraben free options. Sephora, a major retailer of cosmetics, sells products that are labeled "paraben-free," and Burt's Bees has never used parabens. Even manufacturers of dermatologic pharmaceuticals provide marketing materials for some topical medications that trumpet the fact that products are "free of parabens."

In actuality, parabens are not a major cause of ACD. The paraben controversy has arisen because studies have suggested that parabens can mimic the activity of estrogen, and thus may serve as an endocrine disrupter. Parabens have also been detected in human breast tumor tissue [6]. As controversy over the use of parabens has reached the mainstream media [7], patients have received the impression that parabens are uniformly bad.

Although parabens are the most commonly used preservatives in cosmetic and pharmaceutical products, allergy is quite rare [8]. In the 2001-2002 study period, The North American Contact Dermatitis Group tested patients with a screening series of 65 allergens. Based on frequency of positive reactions, paraben mix was ranked in the bottom 10 allergens, with only 0.6 percent of patients tested showing a reaction [9]. Despite topical medications being marketed as paraben-free, dermatologists with a special interest in contact dermatitis are not overly concerned with the presence or absence of parabens.

Baby products smell better, but are not necessarily safe for sensitive skin

Patients and physicians may presume that products designed for babies are designed to be gentle to the skin. This is why some patients with eyelid dermatitis are commonly instructed by ophthalmologists to stop using soap and to instead cleanse their eyelids with Johnson's® Baby Shampoo. Patients with perianal dermatitis or generalized eczema may also switch to this "gentle" cleanser. However, Johnson's® Baby Shampoo still contains three major allergens, including fragrance, quaternium-15 (a formaldehyde releasing preservative), and cocamidopropyl betaine (a surfactant). Fragrance and quaternium-15 are among the top 10 allergens in the NACDG study [9]. Cocamidopropyl betaine is considered an emerging allergen in the pediatric population [10] and was named the contact allergen of the year in 2004 by the American Contact Dermatitis Society in recognition of its increasing importance as an allergen.

When seeking gentle cleansers, one option would be a soap-free cleanser such as Cetaphil Gentle Skin Cleanser, which lacks the major allergens of fragrance and formaldehyde. Another, older product, Albolene Moisturizing Cleanser (unscented formula), is one that I frequently recommend for gentle cleansing of the eyelids or perianal region. This product is based on mineral oil and petrolatum and liquefies on contact with the skin.

The term nickel free is open to interpretation in the United States

In the European Union, regulations specify that items labeled as nickel free may not contain more than 0.05 percent nickel. In contrast, there is not yet a standard in the United States to define the term nickel free. Manufacturers are thus free to choose their own definition. For example, jewelry may contain a plating or top layer that is free of nickel, while still utilizing nickel alloys in the base metal. When the plating wears thin with time, the patient may be exposed to nickel and then develop dermatitis.

Nickel avoidance can be difficult. Nickel in an object cannot be detected by appearance alone. Its presence or absence in consumer goods is not typically found on a label. It is frequently used as a component in many metal alloys because it is durable and cheap. It can be difficult to suggest an alloy that is safe for patients to use, because only patented and trademarked alloys have standard components. For example, most pewter would be acceptable for use, because pewter contains primarily tin, with lead and antimony added. However, small amounts of other metals, such as nickel, may be added. The same applies to many other alloys. Most, but not all, sterling silver will be free of nickel. The company, James Avery, specifically certifies that their sterling silver jewelry is free of nickel. Most, but not all, yellow gold will be acceptable; by contrast, white gold frequently utilizes nickel to provide the white color. Some companies such as Simply Whispers sell costume jewelry and jewelry components that are free of nickel. (800-451-5700 www.simplywhispers.com)

Given the difficulties with avoidance, nickel-sensitive patients should be advised to use a nickel test kit. These kits, which use dimethylglyoxime, do not harm the object being tested, and will detect the presence of nickel. Although they may not detect all objects that contain nickel, they can prove very useful for patients. (800-365-6868 www.allerderm.com or www.nickelsolution.com)

Gold, despite a reputation as an inert metal, can be an allergen

Gold is a relatively inert metal and not easily solubilized. However, a number of cases demonstrate that gold can cause dermatitis at sites distant from the gold object. In fact, because of an increasing awareness of gold's importance as an allergen, it was named contact allergen of the year in 2001. A study by the NACDG in the study period 1996-1998 evaluated contact dermatitis to gold [11]. This study found that the face and eyelids were involved in approximately one in four patients allergic to gold. In a later study evaluating cases of isolated eyelid dermatitis, the NACDG found that gold was the most common allergen that accounted for pure eyelid dermatitis [12]. Despite the fact that many patients do not exhibit dermatitis at the site of contact with gold jewelry, clearing of dermatitis has occurred when patients stopped wearing gold jewelry [13]. One possible explanation is that titanium dioxide in sunscreens and cosmetics may adsorb gold particles in jewelry, aiding in transfer to the face and eyelids [14].

Soft, pure, and natural 100 percent cotton is not necessarily the fabric of choice

Certain morphologic clues suggest textile dermatitis. Generalized dermatitis, with accentuation at the lateral neck, the waistband, and the periaxillary region with sparing of the axillary vault, is suggestive of textile dermatitis. In this type of allergy, dermatitis is more prominent at areas where sweat and friction enhance contact with the allergen. In some cases, the dermatitis is more pronounced on the inner thighs, the posterior thighs, the upper inner arms, or under the socks.

Given the presence of these clues, one should advise patients that clothing may be the culprit, specifically the dyes or the formaldehyde finishes in the fabric. Many patients are skeptical. The common response is: "Because of my sensitive skin, I only wear 100 percent cotton, so that can't be it."

Of course, cotton clothing has a reputation for being soft, pure, and natural. However, unfinished cotton wrinkles very easily. Thus, formaldehyde, in the form of textile resins, is added to many items of cotton clothing. Some of these items are labeled wash and wear, permanent press, or wrinkle free. However, some cotton items won't be labeled in any specific manner. While garment tags will indicate the fabric used, garment tags will not indicate the presence of formaldehyde finishes.

Although patients are advised to wear loose clothing, and avoid sweating and friction as much as possible, counseling focuses on choosing garments that are made of certain fabrics.

When concerned about formaldehyde, patients should be advised to completely avoid cotton/polyester blends, rayon, and corduroy. Some 100-percent cotton fabrics, particularly those that wrinkle easily, may be safe to use. From a practical standpoint, though, because there is no way to tell for sure if a garment has been finished with a formaldehyde resin, patients need to exercise a great deal of caution with these garments; it may be easier to avoid them altogether. Patients may instead use certain alternative fabric types that are unlikely to be finished with formaldehyde resins. These include 100 percent silk, 100 percent polyester, 100 percent linen (that wrinkles easily), 100 percent wool, and 100 percent denim [15].

Some individuals may switch to organic cotton thinking that it will be better for their skin. A number of major retailers now sell garments made of organic cotton, including Walmart, Target, Victoria's Secret, and Patagonia. However, organic cotton refers to how the cotton is grown. Because pesticides are not used, this type of cotton is almost surely better for the environment. However, organic cotton garments may still be treated with chemical finishes and dyes. A better choice for patients would be to seek out garments labeled "chemical-free." These are much harder to locate and are usually sold through specialty retailers found on the Internet.

Gloves don't protect against all allergens

Some patients present to the dermatologist with hand eczema. "My doctor told me to wear gloves, and even though I've been wearing gloves religiously, my hands are still breaking out." In counseling patients with contact dermatitis, avoidance of the allergen is a must. If the patient has ongoing exposure to the allergen, that includes providing counseling on effective barrier methods. Unfortunately, there are several allergens that easily penetrate common gloves (including vinyl and latex rubber gloves). Orthopedic surgeons, for example, are well aware of the hazards of acrylate monomers found in bone cement. Studies find that these monomers can penetrate surgical rubber gloves within minutes [16]. Workers in other occupations may unknowingly use inappropriate barriers. Hairdressers with hand dermatitis may use vinyl gloves as protection. However, glyceryl monothioglycolate, an allergen found in perming solutions, penetrates vinyl gloves easily. Health care workers are at risk as well. In one case, a dental hygienist presented with dermatitis primarily on the 2nd and 3rd fingers of her right hand. Although this was where she held her instruments, she doubted that the instruments were the cause, because she always handled them with latex rubber gloves. Patch testing revealed a strong reaction to glutaraldehyde. Glutaraldehyde is used in cold sterilization, so is used for items such as dental instruments and endoscopy equipment. It is also used as a disinfectant, and is found in some hospital brands such as Cidex. Avoidance can be a challenge because glutaraldehyde penetrates latex gloves easily and gloves made of neoprene may actually absorb the substance.

In a household setting, some patients use two-part epoxy glues. Gloves such as vinyl gloves would be an inadequate barrier. A type of glove formulated for chemical exposure of this type would include the Silver Shield/4H gloves. (1-800-365-6868 www.allerderm.com and 1-800-430-4110 www.northsafety.com)

References

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2. Fowler J, Taylor J, Storrs F, Sherertz E, Rietschel R, Pratt M, et al. Gold allergy in North America. Am J Contact Dermat 2001;12:3-5. PubMed

3. Rietschel RL, Fowler JF Jr., Fisher's Contact Dermatitis, 5th ed. Philadelphia: Lippincott. Williams & Wilkins, 2001: 35: 641.

4. www.cfsan.fda.gov. Hypoallergenic cosmetics. U.S. food and Drug Administration Center for Food Safety and Applied Nutrition Office of Cosmetics and Colors Fact Sheet. December 19, 1994; revised October 18, 2000.

5. Scheinman PL. Exposing covert fragrance chemicals. Am J Contact Dermat 2001;12:225-228. PubMed

6. Harvey PW, Darbre P. Endocrine disrupters and human health: could oestrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women? J Appl Toxicol 2004;24:167-76. PubMed

7. Deardorff J. Concern rises over effects of parabens. September 4, 2007. www.chicagotribune.com

8. Cashman AL, Warshaw EM. Parabens: a review of epidemiology, structure, allergenicity, and hormonal properties. Dermatitis 2005;16:57-66. PubMed

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10. Militello G, Jacob SE, Crawford GH. Allergic contact dermatitis in children. Curr Opin Pediatr 2006;18:385-90. PubMed

11. Fowler JF. Gold. Am J Contact Dermat 2001;12:1-2. PubMed

12. Rietschel RL, Warshaw EM, Sasseville D, Fowler JF, DeLeo VA, Belsito DV, et al. Common contact allergens associated with eyelid dermatitis: data from the North American Contact Dermatitis Group 2003-2004 study period. Dermatitis 2007;18:78-81. PubMed

13. Ehrlich A, Belsito DV. Allergic contact dermatitis to gold. Cutis 2000;65:323-6. PubMed

14. Nedorost S, Wagman A. Positive patch-test reactions to gold: patients' perception of relevance and the role of titanium dioxide in cosmetics. Dermatitis 2005;16:67-70. PubMed

15. Carlson RM, Smith MC, Nedorost ST. Diagnosis and treatment of dermatitis due to formaldehyde resins in clothing. Dermatitis 2004;15:169-75. PubMed

16. Darre E, Vedel P, Jensen JS. Skin protection against methylmethacrylate. Acta Orthop Scand. 1987;58:236-238. PubMed

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