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Review Essential of Care Cosmetics

Aurora Alessandrini * and Bianca Maria Piraccini

Division of Dermatology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna 40138, Italy; [email protected] * Correspondence: [email protected]; Tel.: +39-051-214-3677; Fax: +39-051-214-4867

Academic Editors: Won-Soo Lee and Enzo Berardesca Received: 18 July 2016; Accepted: 20 September 2016; Published: 27 September 2016

Abstract: Nowadays, and style play a very important role in people’s physical aspect and self-perception. Hair cosmetics can be distinguished into two main categories: cosmetics with temporary effect on the hair, for example , conditioners, sprays, and temporary colors; and cosmetics with permanent effect on the hair, such as permanent , , bleaches and permanent colors. These cosmetic procedures may induce hair abnormalities. We provide an overview on the most important characteristics of these procedures, analyzing components and effects on the hair. Finally, we evaluated new camouflage techniques and tattoo .

Keywords: hair; hair care; hair care cosmetics; hair care products; cosmetic ingredient; healthy hair

1. Introduction Hair is a complex structure composed by many components that act as a unit, with the biological purpose of protecting the scalp, as well as physical attractiveness to the self-perception of beauty. Nowadays, hair care and style play a very important role in people’s lives, both for men and women, so knowledge of hair products, mode of action, efficacy, ingredients and hair procedures has become more relevant in dermatologists’ medical practice. The amount of money spent to enhance the hair beauty is an indication of how much attention is given today to the hair appearance. On the other hand, these data are emphasized in patients suffering from hair disease. Hair cosmetics are also an important tool for increasing patient’s adhesion to scalp treatments, according to the diversity of hair types and ethnicity. Trueb [1] described them as “preparations intended for placing in contact with the hair and scalp, with the purpose of cleansing, promoting attractiveness, altering appearance, and/or protecting them in order to maintain them in good condition”. Hair cosmetics can be distinguished into two main categories:

(1) Cosmetics with temporary effect on the hair, for example shampoos, conditioners, sprays, and temporary colors; and (2) Cosmetics that produce permanent effect on the hair shaft, such as permanent waves, relaxers, bleaches and permanent colors.

2. Shampoos Shampoos are the most commonly prescribed treatment for hair and scalp. In the past, was the only available for the hair, while the introduction of the first non-alkaline date back to 1933 [2]. The modern society requires many features in a formulation: a shampoo has primarily to clean the scalp and the hair, but also has to be cosmetically pleasing, not dry out the hair, not irritate the skin, improve hair beautification, and be less expensive.

Cosmetics 2016, 3, 34; doi:10.3390/cosmetics3040034 www.mdpi.com/journal/cosmetics Cosmetics 2016, 3, 34 2 of 10

A shampoo consists of 10–30 ingredients [2], classified according to their different activities. These ingredients include: (1) cleansing agents, called , that remove sebum or skin scale; (2) conditioning agents that give softness to the hair; (3) active ingredients, for treating specific disease s like ; and (4) additives, such as , that contribute to the stability and comfort of the product. Every ingredient is tested, officially approved and declared on the label. Thanks to agents, a shampoo can remove dirty particles and sebum from the scalp and from the hair shafts, but this cleansing activity has to be mild in order to avoid complete removal of the natural oils and sebum from the skin. Modern shampoos are sensitive on skin or mucous membranes, and the development of contact is rare, due to the short contact time of the shampoo with the scalp. Typical ingredients of shampoos are foaming agents and detergent agents, which prevent the formation of insoluble soap on hair and scalp. Surfactant agents are the most important cleaning substances of shampoos, thanks to their molecular structure. In particular, one end of the molecule has a negative electrical charge and is soluble in , so it does not blend with oils. The other end is soluble in oil and grease and does not blend with water. These molecules surround the fragments of grease localized on hair and scalp: the oil soluble parts go into the grease and the water-soluble parts remain located outward, forming a hydrophilic mass that is totally negatively charged. The surface of the hair shaft has negative charges, which tend to force the mass negative charges apart, resulting in a reduction of tension between water and grease on the surface, and production of , which incorporates the dirt, so that it cannot be re-deposited on the hair and scalp. Conditioning molecules contained in shampoos combine the cleansing action with the function to impart manageability, gloss and antistatic properties of the hair. This conditioning shampoos are composed by fatty substances, like vegetable oils, , an derivatives, collagen, animal proteins, quaternium ammonium compounds or cationic (which are the main component of the “2 in 1 shampoo”) and silicone, that reduce the friction obtained by combing the hair, and then the risk of hair shaft damage [2]. Among other substances we can mentioned: glycerin, , and stearalkonium chloride [3]. In particular, protein-derived substances have the property to be attractive by the keratin (“substantivity”), with the result of temporarily adhere the cortex fragments together. Additives of shampoos include ingredients that are able to control the thickness of the formulation like citrate and lactate. Another key consideration is shampoos pH: many of them have an alkaline pH, which causes hair shaft swelling, predisponding the hair to the damage. A neutral pH shampoo is the best choice for chemically treated hair from either permanent dyeing or permanent waving [3]. Other additives include UV absorbers, like benzophenone derivatives and , like ascorbic and α-tocopherol. Preservatives of shampoos prevent bacterial contamination, and include sodium benzoate, , ethylenediaminetetraacetic acid (EDTA), DMDM hydantoin and tetrasodium EDTA. Moreover, most shampoos contain other ingredients like colors, , pearlishing agents, such as natural oils and fatty acid esters, and , such as glycerin and . “Medicated” shampoos contain active ingredients selected to treat medical conditions, mainly seborrheic dermatitis or . Active ingredients include , ciclopirox olamine, zinc , piroctone olamine, tar derivates, , selenium sulfide, poly-vinyl-pyrrolidone, complex, and colloidal sulfur. The combination of cosmetic technology and medical therapy allows the benefits of cosmetic products together with the efficacy of medical agents. Adverse reactions to shampoos are rare. The most common one is accidental contact with the mucous membranes, such as the nose and . If patch testing to a shampoo is required, the shampoos should be diluted to form a 1%–2% aqueous for closed patch testing and a 5% aqueous solution for open patch testing. False positive reactions due to can occur. Patch testing individual ingredients separately is advisable [4]. Cosmetics 2016, 3, 34 3 of 10

3. Conditioners Most of the shampoos contain conditioning agents, but consumers often apply a conditioner after shampooing, to minimize hair frizzing, increasing manageability and gloss of the hair. A conditioner can therefore be used to reduce a chemical or mechanical trauma of the hair, such as permanent dyes, bleaching, and excessive brushing. As already mentioned, the hair shaft has negative electrical charges, while conditioning agents have positive charges: conditioners acts by neutralizing the electrical negative charge of the hair fiber by addicting positive charges and by greasing the cuticle, with the final result of reduce fiber hydrophilicity [5]. Conditioners also help the raised cuticles to lie down against the hair surface, and in this way preserve hair color and enhance its shyness and smoothness too. Common ingredients of conditioners include mainly cationic surfactants, like cetyltrimethylammonium chloride, behentrimonium, propyltrimonium, and stearamidopropyl dimethylamine. Polymers, like mono and polypeptides like hydrolyzed proteins (amino ), polypeptides derived from collagen and polyvinylpyrrolidone (PVP), fill the hair shaft defects, creating a smooth surface to increase shine while eliminating static electricity thanks to its cationic nature [3]. Emollients/oily compounds are composed of natural or synthetic oils, but also esters and . , oil, or grape seed oil are some of these natural oils. The most frequently used synthetic and active oils are silicones (e.g., dimethicone, dimethiconol, amodimethicone and cyclomethicone). Dimethicone is the most widely used silicone in hair care cosmetics, with the effect of protecting the hair shaft from abrasive actions. Other conditioners components are: fatty alcohols (e.g., and ), waxes (e.g., and paraffin wax), gums (e.g., ), salt () and emulsifiers like ethoxylated fatty alcohols (e.g., polysorbate-80 or ceteareth-20) [6]. In daily practice, hair conditioners can be used in different ways. Instant conditioners are applied immediately after shampooing and rinsed off after few minutes, while deep conditioners, formulated usually in creams, can remain on hair for 20–30 min with an increase of their penetration. Blow drying are another formulation that can be left on the hair because are oil-free. They are very useful for people with fine hair or excessive scalp sebum. A particular type of conditioner, called hair glaze or hair thickeners conditioners, increase hair diameter by coating the hair shaft. Similar to conditioners, they usually contain proteins.

4. Hair Color Products

4.1. Hair Dyes In modern society, people want to change the hair color according to the trends of the moment, and thanks to developments in the field of dyestuffs, now this desire can be obtained in a few minutes. Nowadays, hair dyes are utilized by both men and women to modify natural hair color or restore pigmentation once graying has set in. Modern hair dyes can be classified into three categories: temporary, semi-temporary and permanent. The main difference between them is their capacity to reach the hair cortex, obtained by an alkaline pH. In many of these products, ammonia or ethanolamine are addicted to increase the pH [5]. Temporary colors are applied in the form of shampoos, lotions or foam and change the hair color for a relatively short time, normally until the first wash. They are generally used to add color highlights, remove yellowish hues from white hair, or cover up few graying . Ingredients of temporary colors are products with a high molecular weight, which simply deposit on the cuticle of the hair and are then removed easily. The dye is bonded to a cationic to reduce its solubility and increase its affinity to hair. The resulting complex is dispersed in a base using surfactants to make the final product [7]. Cosmetics 2016, 3, 34 4 of 10

One example is , obtained from the plant Lawsonia alba, which is used on skin and nails, too. In the literature, few cases of allergic to henna have been described [5,8]. Cosmetics 2016, 3, 34 4 of 10 Semi-permanent colors are composed by ingredients like nitroaromatic amines or aromatic dyes (of low molecularOne example weight), is henna, which obtained do not from bind the toplant the Lawsonia hair protein alba, which because is used they on do skin not and oxidize: nails, they are watertoo. In soluble, the literature, so they few can cases be of washed allergic outcontac aftert dermatitis usually to 6–10 henna wash have cycles been described or earlier. [5,8]. They do not contain ammoniaSemi-permanent or ethanolamine, colors are composed but hydrogen by ingred peroxideients like or resorcinolnitroaromatic can amines be present. or aromatic Themain purposedyes of (of semi-permanent low molecular weight), colors which is to color do not white bind hairto the or hair to give protein more because tone tothey the do natural not oxidize: color, but they cannotthey are lightenwater soluble, hair. One so they important can be washed characteristic out after isusually low molecular 6–10 wash weight,cycles or which earlier. enables They do these productsnot contain to diffuse ammonia into theor ethanolami middle layersne, but of hydrogen the cuticle peroxide without or binding resorcinol firmly can be to present. the hair The protein main purpose of semi-permanent colors is to color white hair or to give more tone to the natural itself [9]. Consequently, the application of semi-permanent colors does not require any prior hair color, but they cannot lighten hair. One important characteristic is low molecular weight, which modification,enables these required products instead to diffuse by permanent into the middle hair color.layers of the cuticle without binding firmly to the Permanenthair protein itself hair [9]. dyeing Consequently, is a process the applicat that permanentlyion of semi-permanent changes thecolors color does of not the require hair, any through a chemicalprior hair reaction modification, of oxidation, required instead which by allows permanent the molecules hair color. of color to penetrate into the hair. PermanentPermanent colors allow hair dyeing darkening is a process or brightening that permanently hair color, changes and are the resistantcolor of the to anyhair, externalthrough a factor, includingchemical washings, reaction forof oxidation, 4–6 weeks. which They allows offer the many molecules range of ofcolor hues to andpenetrate can coverinto the the hair. highest gray-hairPermanent numbers. colors allow darkening or brightening hair color, and are resistant to any external factor, Theincluding principle washings, consists for 4–6 in theweeks. penetration They offer of many the coloringrange of moleculeshues and can into cover pores the of highest hair shaft (previouslygray-hair increased numbers. in size, by hydration and alkalinization). At this point, the molecules are The principle consists in the penetration of the coloring molecules into pores of hair shaft oxidized and assume color, which is transmitted to the keratin of the cuticle and the cortex, mimicking (previously increased in size, by hydration and alkalinization). At this point, the molecules are naturaloxidized melanin and granules. assume color, which is transmitted to the keratin of the cuticle and the cortex, Duringmimicking these natural reactions, melanin some granules. intermediates are formed, usually derivates of p-phenylenendiamine (PPD), responsibleDuring these for darkreactions, brown andsome black intermed shades,iates or ofarep -aminophenol,formed, usually responsible derivates for blondeof colors.p-phenylenendiamine Some dyes contain (PPD), also resorcinol, responsible but for many dark companiesbrown and haveblack eliminatedshades, or of it forp-aminophenol, security reasons. PPDresponsible is an hapten for (an blonde incomplete colors. antibody Some dyes stimulating contain also substance), resorcinol, which but canmany combine companies with have a protein moleculeeliminated in the it skin,for security leading reasons. to sensitization, PPD is an hapten which (an in incomplete future reapplication antibody stimulating will substance), to an allergic reaction.which Allergic can combine skin reactions with a protein to PPD molecule may have in differentthe skin, severityleading to and sensitization, sometime includewhich in the future mucosae. reapplication will lead to an allergic reaction. Allergic skin reactions to PPD may have different For these reasons, a skin test, made at least 48 hours before coloring, is mandatory before severity and sometime include the mucosae. For these reasons, a skin allergy test, made at least 48 applying the coloring agent on the scalp in people with suspected PPD sensitization. hours before coloring, is mandatory before applying the coloring agent on the scalp in people with Assuspected mentioned, PPD sensitization. in dyes active ingredients are also present, like hydrogen peroxide, which bleaches out the originalAs mentioned, color and, in dyes oxidizing active theingredients molecules are ofalso the present, dye, activate like hydrogen the colorant peroxide, reactions, which and ammonia,bleaches which out isthe the original alkalizer. color Other and, ingredientsoxidizing the are: molecules chelating of agents, the dye, which activate maintain the colorant chemically stablereactions, peroxideand and ammonia, its activity, which deactivating is the alkalizer. any catalytic Other metalsingredients in the are: product; chelating and agents, solvents, which which help tomaintain improve chemically stable and peroxideand solubilization its ofactivity, the dye; deactivating surfactants, any which catalytic remove metals oil in andthe product; sebum from the hairand surface. solvents, which help to improve viscosity and solubilization of the dye; surfactants, which Dyesremove can oil interfere and sebum with from some the dermoscopichair surface. diagnosis of hair diseases [10]: for example, permanent Dyes can interfere with some dermoscopic diagnosis of hair diseases [10]: for example, dye can penetrate , giving a “black dot” appearance, distinctive for ; permanent dye can penetrate hair follicle, giving a “black dot” appearance, distinctive for alopecia semipermanent dye can deposit on the scalp, mimicking sun exposure or excoriated lesions. areata; semipermanent dye can deposit on the scalp, mimicking sun exposure or excoriated lesions. Long-termLong-term contact contact of of dyes dyes with with the the scalp scalp cancan determinedetermine a acontact contact dermatitis dermatitis which which can cause can cause a a telogentelogen effluvium effluvium (Figure (Figure1), but1), but in in severe severe cases cases can can induce induce edema. edema.

Figure 1. Contact dermatitis of the scalp due to permanent dye. Figure 1. Contact dermatitis of the scalp due to permanent dye.

Cosmetics 2016, 3, 34 5 of 10

As mentioned, PPD is an extremely potent contact sensitizer, allowed at a concentration up of 6% inAs hair mentioned, dyes. Other PPD frequent is an extremely reported potent hair dy contacte sensitizer, are toluene-2,5-diamine, allowed at a concentration allowed up for of use 6% atin a hair concentration dyes. Other up frequent to 10%, reported p-aminophenol hair dye and allergens m-aminophenol, are toluene-2,5-diamine, the last at up to allowed 2% [11]. for use at a concentrationA study [11] up toanalyzed 10%, p-aminophenol chemically the and actualm-aminophenol, content of PPD the and last selected at up to derivatives 2% [11]. in hair dye productsA study causing [11] analyzedallergic contact chemically dermatitis the actual in nine content patients: of PPD more and specifically, selected derivatives chemical inanalysis hair dye of theproducts randomly causing collected allergic products contact identified dermatitis concentr in nineations patients: of the more oxidative specifically, hair dyes chemical similar analysis to the concentrationsof the randomly in collectedthe products products used by identified the patients concentrations with hair dye of thedermatitis. oxidative This hair study dyes shows similar that to patientsthe concentrations can develop in thehair products dye dermatitis used by thefrom patients concentrations with hair lower dye dermatitis. than that Thispermitted study showsin the Europeanthat patients Union can (EU) develop Cosmetic hair dye Directive. dermatitis from concentrations lower than that permitted in the EuropeanIn another Union interesting (EU) Cosmetic study Directive. [12], authors provided a ranking concerning contact allergy risk, analyzedIn another the predictions interesting for study sensitization [12], authors potential provided of 229 a hair ranking dyes concerningsubstances: contactas result, allergy about risk, the 75%analyzed of all thehair predictions dyes were forpredicted sensitization to be strong potential/moderate of 229 hairsensitizers, dyes substances: even stronger as result, than aboutPPD, and the many75% of of all these hair dyesare not were currently predicted used to befor strong/moderate diagnosing contact sensitizers, allergy to even hair stronger dyes. PPD than is PPD, resulted and moremany potent of these than are nottoluene-2,5-diamine, currently used for while diagnosing resorcin contactol seems allergy to be to less hair potent dyes. PPDthan isPPD. resulted Only more 22% ofpotent hair thandye substances toluene-2,5-diamine, were predic whileted to resorcinol be weak seemssensitizers to be and less 3% potent were than predicted PPD. Only to be 22% extremely of hair weakdye substances or non-sensitizing. were predicted to be weak sensitizers and 3% were predicted to be extremely weak or non-sensitizing.More recently, Uter et al. [13] assembled complete information on the current practice of using hair cosmetics,More recently, creating Uter a etnew al. [European13] assembled hair cosmetics complete informationseries. They collected on the current all allergens practice of of proven using importancehair cosmetics, for creatingpatients awith new contact European allergy hair to cosmetics hair cosmetics, series. They and collectedalso allergens all allergens with less of proven importance,importance forunderlining patients withthe need contact to evaluate allergy to thes haire cosmetics,substances andin specialized also allergens departments, with less provenand to createimportance, a cosmetovigilance underlining thenetwork. need to evaluate these substances in specialized departments, and to create a cosmetovigilance network. 4.2. Bleaching Agents 4.2. Bleaching Agents These products provide permanent hair lightening without the addition of a coloring tint, thanksThese to substances products provide like hydrogen permanent peroxide, hair lightening ammonia without and persulfate the addition salts. of aThe coloring process tint, requires thanks timeto substances and is realized like hydrogen by a series peroxide, of color ammonia stages. As and mentioned, persulfate hydrogen salts. The peroxide process requires bleaches time out andthe originalis realized color by of a seriesthe hair. of colorThe oxidizing stages. As agent, mentioned, in alkaline hydrogen solution, peroxide penetrates bleaches into the out cortex the original of the hair,color after of the raising hair. The the oxidizingscales of the agent, cuticle, in alkaline and ch solution,emically penetratesmodifies the into melanin: the cortex as ofresult, the hair, melanin after granulesraising the are scales dissolved, of the cuticle,leaving and tiny chemically gaps in the modifies cortex the [7]. melanin: For this as reasons, result, melanin repeated granules bleaching are treatmentsdissolved, leavingcan cause tiny an gaps increased in the cortex porosity [7]. Forof hair this reasons,and permanently repeated bleachingraised scales, treatments leading can to cause hair weatheringan increased (Figure porosity 2). of hair and permanently raised scales, leading to hair weathering (Figure2).

(a) (b)

Figure 2. (a) Hair weathering caused by repeatedrepeated bleaching treatment; and ( b) important hair shaft damage of hair weathering, clearly visible with microscopic examination.

Persulfates can trigger immunomediate reactions, such as rhinitis, asthma, contact urticarial Persulfates can trigger immunomediate reactions, such as rhinitis, asthma, contact urticarial and and even anaphylaxis, but the exact immune mechanism is still unknown [14]. even anaphylaxis, but the exact immune mechanism is still unknown [14].

Cosmetics 2016, 3, 34 6 of 10 Cosmetics 2016, 3, 34 6 of 10

5. Hair Hair Styles Styles

5.1. Permanent Waves The topical application of cosmetics in lotions or sprays may give hair a temporary different “style”“style” thatthat isis lostlost afterafter thethe firstfirst shampooing.shampooing. A A modification modification of of hair hair internal internal chemical chemical structure structure with with a specifica specific chemical chemical process process is is needed needed to to change change in in a permanenta permanent way way the the shape shape of of the the hair. hair. A permanent wave is a process that makes curly the hair, using chemicals that break and reform the strong disulfidedisulfide bonds of the hair shaft. First th thee hair is washed and wrap around the curler (the amplitude of which will determinate the thickness of the curl), then waving in alkaline base is then applied (the most commonly used is ammonium thioglycolate):thioglycolate): it raises the scales of the cuticle and, reaching inside the cortex, breaks breaks the the disulf disulfideide bonds bonds that that give give the the natural natural shape shape of of the the hair. hair. After a fixedfixed time the waving lotion is removed withwith the rinse and a neutralizerneutralizer is applied, which contains oxidizingoxidizing agents,agents, like like hydrogen hydrogen peroxide, peroxide, that that rebuild rebuild the disulfidethe disulfide bonds bonds in a differentin a different order, stabilizingorder, stabilizing the new the shape new ofshape the hair.of the Hair hair. waving Hair waving is for this is reasonfor this the reason most the dangerous most dangerous cosmetic procedurescosmetic procedures for the hair for and the shouldhair and be should monitored be monitored carefully. carefully. Trichorrhexis nodosa is frequent in bleached andand permed hair. The damage to the cuticle cells makes them detach and lead to exposure to the hair shaft cortex. The hair shaft shows small whitish knots visible with thethe unaidedunaided eye.eye. The hair is fragilefragile andand shortshort duedue toto breakage.breakage. Microscopic observation of the hair shaft shows one or more kn knotsots that easily break off producing two brush-like tips (Figure3 3).).

Figure 3. MultipleMultiple Knots Knots easily easily break break off, off, producing two brush-like tips, are typical hair shaft abnormalities of trichorrhexis nodosa.

5.2. Relaxers 5.2. Relaxers The mechanisms of relaxing is the breaking of hair disulfide bonds, re-forming of hair shape The mechanisms of relaxing is the breaking of hair disulfide bonds, re-forming of hair shape and and re-making of the linkages. The shape of the hair changes from curly to straight. Multiple re-making of the linkages. The shape of the hair changes from curly to straight. Multiple procedures procedures or prolonged time of exposure to the may be needed to straighten tightly curled or prolonged time of exposure to the relaxer may be needed to straighten tightly curled hair, such as hair, such as that of African-Americans, producing hair weathering and breakage. that of African-Americans, producing hair weathering and breakage.

5.3.5.3 Hair Straightening In the past, hair straightener procedure consisted on applying petrolatum based oils on the hair combined with hot irons or hot combs pressedpressed toto thethe hair,hair, butbut thethe effecteffect waswas onlyonly temporary.temporary. Nowadays, hair straighteners are called chemical relaxers,relaxers, and the effect of hair straightening is permanent. ThanksThanks toto the the high high pH pH (9.0–14.0), (9.0–14.0), the the solution solution inflate inflate the hair,the openinghair, opening cuticle cuticle scales, scales, which − allowswhich theallows alkaline the alkaline agent (OH agent−) to (OH penetrate) to penetrate into the hair into fibers the uphair to fibe thers endocuticle. up to the Theendocuticle. straightening The straightening product reacts with keratin, breaking and rearranging the disulfide bridges, which making the spiral keratin molecule soft and stretched [5]. This procedure needs to be repeated every 12 weeks or longer.

Cosmetics 2016, 3, 34 7 of 10 product reacts with keratin, breaking and rearranging the disulfide bridges, which making the spiral keratin molecule soft and stretched [5]. This procedure needs to be repeated every 12 weeks or longer. Alkaline straighteners contain 1%–10% sodium hydroxide (lye-relaxer), lithium hydroxide, Cosmeticscalcium 2016 hydroxide, 3, 34 or a combination of these ingredients such as guanidine carbonate and calcium7 of 10 hydroxide (no-lye relaxers). Ammonium thioglycolate is another “no-lye” relaxers, which selectivity weakensAlkaline the hair straighteners cysteine bonds: contain it is1%–10% then oxidized sodium by hydroxide hydrogen peroxide(lye-relaxer), and, lithium applying hydroxide, a hot iron calciumduring thehydroxide process, or the a combination hair straightening of these can ingr beedients obtained. such Thyoglycolate as guanidine and carbonate hydroxides and are not hydroxidemutagenic (no-lye or carcinogenetic. relaxers). Ammonium The main adverse thioglycolate effects is of another hair straightening “no-lye” relaxers, are scalp which burns selectivity and hair weakensbreakage. the In particular,hair cysteine in bonds: the study it is of then Shetty oxidized et al., theby hydrogen most common peroxide adverse and, effects applying reported a hot afteriron duringchemical the hair process, straightening the hair were: straightening frizzy hair can in 67%,be obtained. dandruff Thyoglycolate in 61%, and in hydroxides 47%, thinning are andnot weakeningmutagenic or of carcinogenetic. hair in 40%, greying The main of hair adverse in 22%, effect ands split of hair ends straightening in only 17% are [15 ].scalp burns and hair breakage.A keratin In particular, treatment in containing the study ,of Shetty et al., athe well-known most common carcinogen adverse has effects been reported performed after in chemicalBrazil with hair success: straightening soon the were: frizzy vigilance hair in organizations 67%, dandruff in Brazilin 61%, (Agência hair loss Nacional in 47%, thinning de Vigilância and weakeningSanitária) prohibited of hair in 40%, the use greying of any of product hair in 22%, containing and split formaldehyde ends in only in 17% concentrations [15]. above 0.2% for cosmeticsA keratin [ 16treatment]. Afterward, containing the formaldehyde formaldehyde, was a well-known replaced by acarcinogen potentially has more been mutagenic performed and in Brazilneurotoxic with product, success: glutaraldehyde, soon the health which vigilance belong toorganizations the same aldehyde in Brazil group, (Agência sold as aNacional homemade de Vigilânciatreatment. Sanitária) The ingredients prohibited used the today use do of notany contain product any containing of these twoformaldehyde substances, in but concentrations are based on aboveformaldehyde-releasers 0.2% for cosmetics such [16]. as Afterward, methylene the glycol formaldehyde or glyoxylic was acid. replaced Acute contactby a potentially dermatitis more may mutagenicoccur as adverse and neurotoxic effect in previously product, glutaraldehyde, sensitized patients which [16 ].belong to the same aldehyde group, sold as a homemade treatment. The ingredients used today do not contain any of these two substances, but6. Hair are based Extensions on formaldehyde-releasers such as methylene glycol or glyoxylic acid. Acute contact dermatitisHair extensions may occur haveas adverse become effect worldwide in previously increasingly sensitized popular, patients either [16]. as a beauty accessory for healthy people both as an aesthetic aid for patients with hair loss. 6. HairThey Extensions are composed by synthetic or human hair, which can be attached to natural hair with various techniquesHair extensions like strand-by-strand, have become the worldwide weft or the increasingly clip-in methods. popular, The either cuticles as ofa beauty the extensions accessory must for healthybe aligned people in the both same as direction an aesthetic of the aid natural for patients hair and with they hair are loss. usually no longer than twice the length of theThey person’s are composed natural hair by for synthetic a cosmetically or human harmonious hair, which result. can be attached to natural hair with variousAmong techniques local side like effects, strand-by-strand, we can mention the traction weft alopecia,or the clip-in secondary methods. to the pullingThe cuticles force appliedof the extensionsto the hair folliclemust be over aligned time in [17 the] (Figure same4 direction), pruritus, of tenderness,the natural andhair localand they pain. are Hair usually matting, no whichlonger thandescribes twice reversible the length or of irreversible the person’s tangling natural of hair locks for of a hair cosmetically that stick together,harmonious can result. occur [18 ] (Figure5). AmongAllergic contactlocal side dermatitis effects, orwe contact can mention anaphylaxis traction can arisealopecia, after secondary sensitization to tothe glues pulling or natural force appliedrubber latexto the that hair is follicle incorporated over time into [17] the (Figure adhesive 4), forpruritus, hair extensions. tenderness, and local pain. Hair matting, whichTrichobezoars describes reversible formed byor theirreversible consumption tangling of hair of locks extension of hair is a that rare stick cause together, of Rapunzel can syndrome,occur [18] which(Figure requires 5). and psychiatric examination [19,20].

(a) (b)

Figure 4.4.( a)(a Small) Small alopecic alopecic patch patch at the siteat ofthe attachment site of ofattachment previous hairof extension;previous (hairb) Dermoscopic extension; (aspectb) Dermoscopic of traction aspect alopecia: of traction multiple alopecia: broken hairsmultiple in a broken non scarring hairs in patch a non of scarring alopecia. patch of alopecia.

Allergic contact dermatitis or contact anaphylaxis can arise after sensitization to glues or natural rubber latex that is incorporated into the adhesive for hair extensions. Trichobezoars formed by the consumption of hair extension is a rare cause of Rapunzel syndrome, which requires surgery and psychiatric examination [19,20]. A case of homicidal strangulation by victim’s own artificial hair extensions has also been described [21].

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Cosmetics 2016, 3, 34 8 of 10

Figure 5. Hair matting developed at the site of attachment of extensions. Figure 5. Hair matting developed at the site of attachment of extensions.

7. Camouflage and Tattooing A case of homicidal strangulation by victim’s own artificial hair extensions has also been describedPeople [21 experiencing]. Figure 5. alopeciaHair matting undergo developed emotional at the site distress of attachment from their of extensions. condition, but fortunately many new techniques have been developed to hide some hair disease. 7. Camouflage CamouflagePatients affected and and Tattooing Tattooing by alopecia areata can cover the scalp using many different styles of hairpieces, which are made with human or synthetic hair fibers tied or woven to a fabric base. In People experiencing alopecia undergo emotional distress from their condition,condition, but fortunately particular, human hair wigs are the most expensive, and they need to be washed and styled every many new techniques have been developeddeveloped to hidehide somesome hairhair disease.disease. two weeks, lasting 2–3 years. Synthetic wigs are stronger and easier to maintain. Types of hairpieces Patients affectedaffected by by alopecia alopecia areata areata can covercan co thever scalp the usingscalp manyusing different many stylesdifferent of hairpieces,styles of include: wig, demiwig, toupees, fall, cascade and wiglet [22]. Allergic contact dermatitis due to whichhairpieces, are madewhich with are made human with or synthetichuman or hair synthetic fibers tiedhair orfibers woven tied toor a woven fabric base.to a fabric In particular, base. In incorporated glues or natural rubber latex car occur (Figure 6). humanparticular, hair human wigs are hair the wigs most are expensive, the most andexpensive, they need and to they be washedneed to andbe washed styled everyand styled two weeks, every lastingtwo weeks, 2–3 years. lasting Synthetic 2–3 years. wigs Synthetic are stronger wigs are and stro easiernger to and maintain. easier Typesto maintain. of hairpieces Types of include: hairpieces wig, demiwig,include: wig, toupees, demiwig, fall, cascade toupees, and fall, wiglet cascade [22]. Allergicand wiglet contact [22]. dermatitis Allergic contact due to incorporateddermatitis due glues to orincorporated natural rubber glues latex or natural car occur rubber (Figure latex6). car occur (Figure 6).

Figure 6. Severe contact dermatitis of the scalp due to wig glue.

Pigmented hair and thickening fibers are effective to cover scalp alopecia in patients with epidermolysis bullosa [23] or androgenetic alopecia [24]. Figure 6. Severe contact dermatitis of the scalp due to wig glue. They act bondingFigure to the 6. hairSevere by static contact electricity, dermatitis so of theit appear scalp due thicker. to wig A glue. fixative spray applied on fibers can increase their stability. Pruritus and irritation and skin irritation can occur. Pigmented hair and thickening fibers are effective to cover scalp alopecia in patients with APigmented split or hairflattened and thickeninghair direction fibers around are effective the parietal to cover whorl scalp (PW) alopecia can inbe patientscosmetically with epidermolysis bullosa [23] or androgenetic alopecia [24]. unpleasant.epidermolysis A scalp bullosa medical [23] or tattooing androgenetic technique alopecia can [camouflage24]. this problem, using a jet black color They act bonding to the hair by static electricity, so it appear thicker. A fixative spray applied on ink ofThey commercial act bonding products, to the with hair byhigh static satisfaction electricity, of sothe it patient appear and thicker. no complications A fixative spray [25]. applied on fibers can increase their stability. Pruritus and irritation and skin irritation can occur. fibersA can tattoo increase technique, their stability. called scalp Pruritus micropigmentat and irritationion and (SMP), skin irritation has been can recently occur. developed to A split or flattened hair direction around the parietal whorl (PW) can be cosmetically mimicA splithair orfollicle flattened and hair minimize direction cosmetic around theproble parietalm derived whorl (PW)from canhair be dise cosmeticallyases. It offers unpleasant. good unpleasant. A scalp medical tattooing technique can camouflage this problem, using a jet black color Asolution scalp medicalfor patient tattooing with techniquescarring alopecia, can camouflage alopecia this areata problem, or alopecia using atotalis, jet black chemotherapy color ink of ink of commercial products, with high satisfaction of the patient and no complications [25]. patients,commercial people products, with scalp with highdeformit satisfactionies and many of the other patient problems and no complications[26]. [25]. A tattoo technique, called scalp micropigmentation (SMP), has been recently developed to SMP is a permanent , which use of different hues in a variety of formulas mimic hair follicle and minimize cosmetic problem derived from hair diseases. It offers good and and instruments employing needles in various sizes and shapes. Many factors have solution for patient with scarring alopecia, alopecia areata or , chemotherapy patients, people with scalp deformities and many other problems [26]. SMP is a permanent concealer, which use pigments of different hues in a variety of formulas and viscosities and instruments employing needles in various sizes and shapes. Many factors have

Cosmetics 2016, 3, 34 9 of 10

A tattoo technique, called scalp micropigmentation (SMP), has been recently developed to mimic hair follicle and minimize cosmetic problem derived from hair diseases. It offers good solution for patient with scarring alopecia, alopecia areata or alopecia totalis, chemotherapy patients, people with scalp deformities and many other problems [26]. SMP is a permanent concealer, which use pigments of different hues in a variety of formulas and viscosities and instruments employing needles in various sizes and shapes. Many factors have to be evaluated when performing this technique, like aesthetic factors, presence of scars on the scalp, skin color, hair color, the amount of remaining hair, and the color and viscosity of the pigments used. The SMP process begins by inserting a micro droplet of through the skin and into the upper , using a standard tattoo instrument, which supports between one and six needles cycling between 100 and 150 cycles per second. Multiple sessions are needed to complete the procedure. The operator makes technical and artistic judgments as the process advances, millimeter by millimeter, customizing each treatment on the patient. Risks and complications include infection, to the components in the pigments and magnetic resonance imaging complications, such as swelling and pain from the metals in the pigments. Little is known about the chemical composition, adsorption, distribution, metabolism, and excretion of inks, and other studies are needed to learn more about this procedure.

8. Conclusions Hair styling play a very important role in people’s physical aspect and self-perception. Hair cosmetics is a very interesting evolving field, and hair is costantly investing resources to find new components, molecules and hair procedures. Usually patients with hair disorders are the main actors targeted to these products, but in daily life all people care of hair beauty and health. Dermatologists should always be update on new formulations, hair technique or adverse effects of hair products designed to beautify and modify the hair, in order to better treat hair and scalp contiditions.

Author Contributions: The Authors contribute equally to this work. Conflicts of Interest: The authors declare no conflict of interest.

References

1. Trüeb, R.M. Dermocosmetic aspects of hair and scalp. J. Investig. Dermatol. Symp. Proc. 2005, 10, 289–292. [CrossRef][PubMed] 2. Trüeb, R.M. Shampoos: Ingredients, efficacy and adverse effects. J. Dtsch. Dermatol. Ges. 2007, 5, 356–365. [CrossRef][PubMed] 3. Draelos, Z.D. Shampoos, conditioners, and camouflage techniques. Dermatol. Clin. 2013, 31, 173–178. [CrossRef][PubMed] 4. De Groot, A.C.; Weyland, J.W.; Nater, J.P. Unwanted Effects of Cosmetics and Used in Dermatology; Elsevier: Amsterdam, The Netherlands, 1994; pp. 473–476. 5. Dias, M.F.R.G. Hair cosmetics: An overview. Int. J. Trichology 2015, 7, 2–15. [CrossRef][PubMed] 6. Souza, P.; Rathi, S.K. Shampoo and conditioners: What a dermatologist should know? Indian J. Dermatol. 2015, 60, 248–254. [PubMed] 7. Guerra-Tapia, A.; Gonzalez-Guerra, E. Hair cosmetics: Dyes. Actas Dermosifiliogr. 2014, 105, 833–839. [CrossRef][PubMed] 8. Thorén, S.; Yazar, K. Contact allergens in ‘natural’ hair dyes. Contact Dermat. 2016, 74, 302–304. [CrossRef] [PubMed] 9. Neuser, F.; Schlatter, H. Hair dyes. In Cosmetic Dermatology: Products and Procedures; Draelos, Z.D., Ed.; Wiley-Blackwell: Oxford, UK, 2010; pp. 256–310. 10. Angra, K.; LaSenna, C.E.; Nichols, A.J.; Tosti, A. Hair dye: A trichoscopy pitfall. J. Am. Acad. Dermatol. 2015, 72, e101–e102. [CrossRef][PubMed] Cosmetics 2016, 3, 34 10 of 10

11. Søsted, H.; Rastogi, S.C.; Andersen, K.E.; Johansen, J.D.; Menné, T. Hair dye contact allergy: Quantitative exposure assessment of selected products and clinical cases. Contact Dermat. 2004, 50, 344–348. [CrossRef] [PubMed] 12. Søsted, H.; Basketter, D.A.; Estrada, E.; Johansen, J.D.; Patlewicz, G.Y. Ranking of hair dye substances according to predicted sensitization potency: Quantitative structure-activity relationships. Contact Dermat. 2004, 51, 241–254. [CrossRef][PubMed] 13. Uter, W.; Bensefa-Colas, L.; Frosch, P.; Giménez-Arnau, A.; John, S.M.; Lepoittevin, J.P.; Lidén, C.; White, I.R.; Johansen, J.D. Patch testing with hair cosmetic series in Europe: A critical review and recommendation. Contact Dermat. 2015, 73, 69–81. [CrossRef][PubMed] 14. Hougaard, M.G.; Menné, T.; Søsted, H. Occupational eczema and asthma in a caused by hair-bleaching products. Dermatitis 2012, 23, 284–287. [CrossRef][PubMed] 15. Shetty, V.H.; Shetty, N.J.; Nair, D.G. Chemical hair relaxers have adverse effects a myth or reality. Int. J. Trichology 2013, 5, 26–28. [CrossRef][PubMed] 16. Van Lerberghe, L.; Baeck, M. A case of acute contact dermatitis induced by formaldehyde in hair-straightening products. Contact Dermat. 2014, 70, 384–386. [CrossRef][PubMed] 17. Salibi, A.; Souéid, A.; Dancey, A. Hair braiding (plaiting) and hair extensions: An underestimated danger! J. Plast. Reconstr. Aesthet. Surg. 2014, 67, e206–e207. [CrossRef][PubMed] 18. Yang, A.; Iorizzo, M.; Vincenzi, C.; Tosti, A. Hair extensions: A concerning cause of hair disorders. Br. J. Dermatol. 2009, 160, 207–209. [CrossRef][PubMed] 19. Flaherty, D.C.; Aguilar, F.; Pradhan, B.; Grewal, H. Rapunzel syndrome due to ingested hair extensions: Surgical and psychiatric considerations. Int. J. Surg. Case Rep. 2015, 17, 155–157. [CrossRef][PubMed] 20. Kwong, W.T.; Kalmaz, D. A modern form of Rapunzel syndrome: Trichobezoar composed of synthetic hair extensions. Clin. Gastroenterol. Hepatol. 2014, 12, A33–A34. [CrossRef][PubMed] 21. Al Beraiki, K.H.; Schiwy-Bochat, K.H.; Rothschild, M.A. Homicidal strangulation by victim’s own artificial hair extensions. Int. J. Legal Med. 2011, 125, 459–461. [CrossRef][PubMed] 22. Draelos, Z.D. Camouflage technique for alopecia areata: What is a patient to do? Dermatol. Ther. 2011, 24, 305–310. [CrossRef][PubMed] 23. Harris, A.G.; Kim, M.; Murrell, D.F. Pigmented hair-thickening fibers: A camouflage technique for alopecia in patients with epidermolysis bullosa. Skin Appendage Disord. 2016, 1, 153–155. [CrossRef][PubMed] 24. Cossman, J.P.; Ladizinski, B.; Lee, K.C. Pigmented concealing for the hair loss patient. J. Cosmet. Dermatol. 2013, 12, 322–324. [CrossRef][PubMed] 25. Park, J.H.; You, S.H. Scalp medical tattooing technique to camouflage bifid parietal whorls. Plast. Reconstr. Surg. Glob. Open 2016, 4, e671. [CrossRef][PubMed] 26. Rassman, W.R.; Pak, J.P.; Kim, J.; Estrin, N.F. Scalp micropigmentation: A concealer for hair and scalp deformities. J. Clin. Aesthet. Dermatol. 2015, 8, 35–42. [CrossRef][PubMed]

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