Dermatologic Therapy, Vol. 25, 2012, 481–490 © 2012 Wiley Periodicals, Inc. Printed in the United States · All rights reserved DERMATOLOGIC THERAPY ISSN 1396-0296 INVITED ARTICLE Update on nail cosmetics Julie Jefferson*&Phoebe Rich† *Division of Dermatology, University of Kansas, Kansas City, Kansas and †Oregon Health and Science University, Portland, Oregon ABSTRACT: Nail cosmetics are used by millions of people worldwide who desire smooth, lustrous nails. The nail cosmetic industry continues to expand to meet increasing consumer demand. In 2011 alone, consumers spent $6.6 billion on nail salon services. Although nail cosmetics are relatively safe, poor application techniques can promote disease, deformity, and allergic and irritant contact derma- titis. The foundation for managing nail cosmetic problems is prevention through education. Familiarity with the procedures and materials used in the nail cosmetic industry is necessary in order to recom- mend safe nail care strategies. KEYWORDS: cosmetics, nails Introduction cuticle picking can employ nail overlays as a helpful deterrent (6,7). For many, well-groomed, glossy nails are a symbol In addition, nail cosmetics can be utilized in the of health and youth and are greatly desired (1). The management of brittle, soft, and/or splitting nails significance of nail beautification is deep-seated, (6,7). Brittle nails arise when the water content of often ingrained subconsciously at a young age, and the nail plate falls from roughly 18 to 16% water while nail cosmetics have been traditionally content (2,8). Nail lacquers and moisturizers may reserved for women, the market for male mani- help maintain nail hydration by sealing in moisture cures is rapidly expanding (2). In 2011, US consum- that would alternatively evaporate (2,6). Nail lac- ers spent $6.6 billion on nail salon services alone, quers, hardeners, gels, shellacs, and elongators can excluding the myriad of consumer products avail- serve to physically thicken and strengthen and able in drug stores and department stores (1,3–5). protect soft, weak, or otherwise fragile nails by pro- Many people rely on nail cosmetics to disguise viding an external, durable shell (5–7). and conceal unsightly nail abnormalities (6,7). Although there are no figures that estimate the Lacquer-based nail enamels and ridge fillers may number of women who suffer from allergic and help smooth longitudinal ridging associated with infectious complications of nail cosmetics, the rates aging. Manifestations of psoriatic nail disease appear to be no higher than those associated with such as nail pitting, onychorrhexis, splinter hem- hair salon allergic and infectious problems (1,6). Of orrhages, salmon patches, and onycholysis can be those persons who do suffer complications, many disguised with lacquer (5–7). Nail shape abnor- find that their physicians simply recommend that malities such as brachyonychia can be hidden they stop using nail cosmetics altogether (9). Nail with artificial nail enhancements (6,7). Persons cosmetics are relatively safe – millions of people aiming to break bad habits such as nail biting or worldwide use nail cosmetics with absolutely no adverse effects (6–9). Advising patients to discon- Address correspondence and reprint requests to: Julie tinue using all nail cosmetics is often unnecessary Jefferson, MD, Division of Dermatology, University of Kansas, and could alienate many patients (9). Rather, phy- 3901 Rainbow Blvd, MS 2025, Kansas City, KS 66103, or email sicians should study the techniques and materials [email protected]. used in the nail industry in order to help their 481 Jefferson & Rich enhancement, or alternatively, when the final step (which is often the case for men), the nails are buffed to a shine (8,11). Several suggestions exist to improve the current basic technique. Distal nail plate filing is preferred over clipping, because the latter can sometimes cause cracking and layering (2). When clipping is necessary, the nails should first be softened by soaking, and the cutting implement should be held perpendicular to the nail plate to prevent onycho- schizia (2,8). For this very reason, filing should also be performed at a perpendicular angle (2,8). Many manicurists prefer to remove the cuticles FIG. 1. Onychoschizia. as they could potentially complicate the even application of nail lacquer and predispose nail lacquers, gels, and shellacs to chipping. However, patients safely use nailproducts by recommending the cuticle serves a very important purpose – to preferred nail care strategies and materials and seal the proximal nail fold to the nail plate and alternatives for any offending agents (9). thereby protect the proximal portion of the nail unit from infection with bacteria and/or yeast (2,9). Hence, the cuticles are best left alone. In cases where persons insist that their cuticles must Basic steps of a nail manicure and be at least partially eliminated as they extend too pedicure and medical suggestions far distally if left untouched, recommend that only the most distal portion of each cuticle be The nail manicure is the process by which finger- removed by first soaking the cuticles in water and nails are cleaned, shaped, and sometimes aug- then gently rubbing over them with a wash cloth mented by the application of a nail lacquer or other daily. nail enhancement (9). The pedicure is analogous Chemical cuticle removers commonly contain to the manicure, but involves toenails and the one of the following active ingredients: 2–5% smoothing or filing of any calluses on the plantar sodium hydroxide, 2–5% potassium hydroxide, tri- surface of the foot (9). The ideal nail shape is dic- sodium phosphate, tetrasodium pyrophosphate, tated by shifting trends (2). Currently, the ideal nail or 3–5% of quaternary ammonium compounds in possesses a central, delicate arc without any sharp combination with urea. However, these products corners medially or laterally, so as to create the illu- are not recommended as they can cause nail plate sion of a long, slender finger (2). However, this ideal softening and are a common cause of irritant shape predisposes persons to hang nails, nail plate contact dermatitis, especially when left on for pro- fractures, and ingrown nails (2,10). Rather, nails longed periods of time (2,8). When an allergic should be shaped with a very slight curve with contact dermatitis (ACD) to a chemical cuticle corners left untouched (2). remover is suspected, open patch testing using a A manicure consists of a number of sequential 2% aqueous concentration can be performed (2). steps (9). First, the nails are soaked in warm, soapy The use of an adhesive primer is usually all that water to remove any debris and to soften them in is necessary to improve nail enhancement adhe- order to prevent cracking, splitting, and distal hori- sion, and filing is often unnecessary. However, zontal layering (onychoschizia) when clipping when persons insist that filing must be performed (FIG. 1) (2). Brittle nails in particular are very sus- to improve nail enhancement adhesion, assure ceptible to damage when clipped without prior them that filing only 5% of the nail plate, or roughly soaking (2,8). The nails are then trimmed and filed 5 of its 100 cell layers, is more than sufficient to to the ideal shape (4,8). Next, the cuticles are soft- enhance the adhesion of nail products (8). Addi- ened by either applying a chemical cuticle remover tionally, recommend that use of heavy grit abra- or soaking in warm water (8,9). Once soft and mal- sives with less than 180 grit and electric files be leable, the cuticles are pushed proximally and/or avoided, alternatively using safer, smoother abra- clipped away with a metal implement (8,9). The sive files with over 180 grit instead (12). Persons surface of the nail plate is then sometimes filed to should be informed that longitudinal ridges do not improve adhesion of nail lacquer or other nail represent areas of increased plate thickness and 482 Update on nail cosmetics thus should not be filed flat as this can result Colorants are primarily utilized in their “lake” in severe local plate thinning and subsequent forms, meaning that their organic forms have splitting. been co-precipitated or absorbed into inorganic, insoluble forms such as oxides, silicilates, or sul- fates of various metals (2,11). Shimmer effects are typically created by incorporating powdered alu- Additional steps of a nail manicure minum, titanium dioxide-coated mica flakes, or pedicure and dermatologic guanine from fish scales, and/or bismuth oxychlo- considerations ride for iridescence (2,11). Newly advertised mag- netic nail lacquers contain iron powder. Prior to solvent evaporation of the applied magnetic nail Nail lacquer lacquer, a magnet in the cap of the lacquer con- Nail salons typically apply a series of coats of nail tainer can be held over the nail, causing the iron lacquer allowing sufficient time for drying between powder in the formulation to gravitate toward the each coat (11). First, one to two base coats are magnet and form a desired pattern. Any polishes applied to further enhance adhesion of the colored containing magnetic materials must be removed nail lacquer to the roughened nail plate (11). Then, prior to magnetic resonance imaging. two coats of colored nail lacquer, followed by one Thixotropic agents are added to colored nail lac- to two top coats are applied (11). The top coat(s) quers for flow control and colorant dispersion and serve(s) to improve the chip-resistant characteris- are not needed in colorless lacquers (11). Most tics of the colored nail lacquer (11). thixotropic agents are clay derivatives with stear- Nail lacquers are composed of four to six types of alkonium hectorite and stearalkonium bentonite ingredients: resins, solvents, plasticizers, colorants, being most commonly used (11). Some colored lac- thixotropic agents, and color stabilizers (11). In quers and top coat lacquers, contain color stabiliz- general, two types of resins are used in various con- ers such as benzophenone-1 and etocrylene, to centrations depending on the desired effect of the safeguard against ultraviolet (UV)-induced color lacquer (2,11).