Dermatology: Practical and Conceptual Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 1 The Contact Sensitivity of Turkish Children and Adolescents to European Baseline Series Allergens between 2013 and 2023 Incilay Kalay Yildizhan1, Ayse Boyvat1 1 Department of Dermatology, School of Medicine, Ankara University, Ankara, Turkey Key words: contact sensitivity, children, pediatric, allergens, patch testing, Turkey Citation: Kalay Yildizhan I, Boyvat A. The Contact Sensitivity of Turkish Children and Adolescents to European Baseline Series Allergens between 2013 and 2023. Dermatol Pract Concept. 2024;14(2):e2024151. DOI: https://doi.org/10.5826/dpc.1402a151 Accepted: November 11, 2023; Published: April 2024 Copyright: ©2024 Kalay Yildizhan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: Both the authors have contributed significantly to this publication. Incilay Kalay Yildizhan: Conceptualization; methodology; Data curation; investigation; writing-original draft; writing-review and editing. Ayse Boyvat: Project administration; supervision; writing- review and editing. Corresponding Author: Incilay Kalay Yildizhan, Ankara Üniversitesi Tıp Fakültesi İbni Sina Hastanesi Yerleşkesi 10. Kat B Blok Sıhhiye 06100, Ankara, Turkey. Phone: +90 505 6547721 Fax number: +90 312 5082231 E-mail: incilaykalay@gmail.com Introduction: Increasing the numbers of patch testing in suspected children increases the rate of  diagnosis of allergic contact dermatitis and the identification of clinically relevant allergens. Objective: The aim of this study was to identify the most frequently observed allergens among Turkish children and adolescents patch-tested in 2013–2023. Methods: The patch test results of 160 patients (age ≤18) were analyzed retrospectively. The frequen- cy of contact allergens and distribution of positive results in terms of sex, age group (children and adolescents), and the presence of atopic dermatitis (AD) were identified. Results: Forty-nine patients (30.6%) (34 girls and 15 boys) exhibited positive patch test reactions to a minimum of one allergen, and contact sensitivity was statistically significantly higher in girls (P=0.034). The five most frequent allergens were nickel sulfate (10.6%), MCI/MI (8.1%), cobalt chlo- ride (5.6%), p-phenylenediamine (PPD) (5%), and MI (3.5%). No significant association was ob- served between patch test positivity and age groups (P>.05). Nickel sulfate sensitivity was significantly higher in girls than in boys (P=.043). A positive reaction was detected in 31.3% of patients with AD and in 33.7% of those without (P>.05), and a statistically significant relationship was observed be- tween contact sensitivity to fragrance allergens and AD (P=.046). Conclusion: Metals and preservatives represent the most frequent allergens in Turkish children and adolescents. Metal sensitivity is expected to decrease as legislation is enforced. Regulatory measures are now required to reduce MI and MCI/MI contact allergy in Turkey. ABSTRACT 2 Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 Introduction The prevalence of pediatric allergic contact dermatitis (ACD) was previously underestimated because traditional ACD was regarded as very rare in children. This derived from the belief that children have an immature immune system and are less frequently exposed to contact allergens [1]. However, recent studies have confirmed an increase in positive patch test re- sults in children [2]. The meta-analysis by Bonitsis et al. [3] reported a higher proportion of positive reactions in studies published after 1995 [4]. The rate of positive patch test reac- tions in the pediatric age group ranges from 27% to 95.6% in recent studies, while relevance ranges from 30.5% to 92.6% [5]. Variations in the prevalence of contact sensitivity to allergens are observed between countries due to differ- ences in allergen exposures, legislations, and local cultures. In previous studies from Turkey, the patch test positivity rate in children ranged between 32% and 57.5% [6-10]. Objective Limited data are available for patch test results among Turkish children. The aim of this study was to determine the prevalence of ACD and the most common allergens in children and adolescents attending our referral patch testing center in Turkey. Materials and Method Approval was granted by the Ankara University Faculty of Medicine ethical committee (n. 02-133-19). One hundred and sixty children and adolescents with clinically suspected ACD who underwent patch testing based on the European Baseline Series (EBS, Chemotechnique Diagnostics, Vellinge, Sweden) at the Ankara University School of Medicine Der- matology Department in 2013–2023 were enrolled. De- mographic characteristics, personal and family histories of atopy, duration, and localization of lesions, and patch test findings were retrieved retrospectively from chart reviews. Localizations were classified as the hands, face/head/neck, leg, trunk, or generalized. Allergen groups were classified as metals, fragrances, preservatives, rubber additives, and top- ical treatments. The patients were divided into two age cat- egories: children (≤10 years) and adolescents (11–18 years). The allergens were applied to the upper back using Van der Bend chambers. These were removed on Day 2, and read- ing was conducted after 30 minutes. A final reading and eval- uation were conducted on Day 4. The results were assessed based on the scoring system recommended by the Interna- tional Contact Dermatitis Research Group (ICDRG) [11]. Reactions of 1+ or more were regarded as positive. Irritant, doubtful, and negative responses were recorded as negative. The EBS underwent several modifications during the study period. Test results based on the EBS applicable during the study period were included in the analysis. SPSS software (SPSS for Windows, Version 15.0, SPSS Inc., USA) was used for statistical analyses. Qualitative vari- ables are expressed as number and percentage values at a 95% confidence interval, while quantitative variables are expressed as mean ± standard deviation (SD). Categorical variables were compared using the chi-square and Fisher’s exact tests, while the Mann-Whitney U and Student’s t tests were applied to compare parametric values. P values <0.05 were considered statistically significant. Results One hundred and sixty children and adolescents aged 2–18 were patch-tested during the study period. The study group consisted of 91 girls (56.9%) and 69 boys (43.1%), with a mean age of 12.4± 4.1 years (median 13 years, range 2–18 years). Sixty-eight (42.5%) patients reported a history of atopy, with a family history of atopy being reported in 31 (19.4%) patients, and personal atopy in 51 (31.9%). Atopic dermatitis (AD) based on the Hanifin and Rajka cri- teria was present in 36 (22.5%) patients [12].The median duration of symptoms was 12 months (mean 22.6±23.9, range 1–120 months). The most common primary site of dermatitis was the hands (n=77, 48.1%), followed by the face/head/neck (n=35, 21.9%), the leg/foot (n=18, 17.4%), and generalized lesions (n=18, 17.4%). Forty-nine patients (30.6%) (34 girls and 15 boys) exhib- ited positive patch test reactions to a minimum of one aller- gen (range 1–7). Thirty-one patients (19.4 %) were positive to one allergen, 13 (8.1%) to two, three (1.9%) to three, one (0.8%) to four, and one (0.8%) to seven. Overall, there were 77 positive reactions to EBS allergens. The distribution of fre- quencies of contact sensitization to EBS allergens is presented in Table 1. The five most common allergens were nickel sul- fate (n=17, 10.6%), MCI/MI (n=13, 8.1%), cobalt chloride (n=9, 5.6%), p-phenylenediamine (PPD) (n=8, 5%), and MI (n=4, 3.5%). Metal allergens were the most common group (n=22, 13.8%), followed by preservatives (n=16, 10%), dyes (n=10, 6.2%), and fragrances (n=7, 4.4%). A significantly higher prevalence of contact sensitivity to cobalt chloride was observed among patients with positive responses to nickel sulfate (P=.008). Four patients with positive reaction to MI and three with positive reaction to MDBG exhibited concomitant sensitivity to MCI/MI (P<.001). The frequencies of contact sensitization to EBS allergens and distributions of positivity according to sex, atopic der- matitis, and age groups are given in Table 1. Prevalences of contact sensitivity were 21.7% in boys and 37.4% in girls. Contact sensitivity was statistically significantly higher Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 3 Ta b le 1 : F re qu en cy o f co nt ac t se ns it iz at io n to E B S al le rg en s an d di st ri bu ti on s of p os it iv it y ac co rd in g to s ex , a to pi c de rm at it is , a nd a ge g ro up . N u m b er o f p o si ti ve re ac ti o n s/ t o ta l n u m b er o f te st ed p at ie n ts Pr ev al en ce % (9 5% C I) Se x N (% ) P va lu e A to p ic D er m at it is N (% ) P va lu e A g e G ro u p N (% ) P va lu e B o y G ir l A D N o n -A D C h ild re n A d o le sc en t Po ta ss iu m d ic hr om at e 0. 5% p et 0/ 16 0 - - - - - - - - - p- Ph en yl en ed ia m in e 1. 0% p et 8/ 16 0 5. 8% 3 (4 .3 ) 5 (5 .5 ) >. 99 1 (2 .8 ) 7 (5 .6 ) .6 85 1 (1 .9 ) 7 (6 .5 ) .2 72 T hi ur am m ix 1 .0 % p et 1/ 16 0 0. 6% - 1 (1 .1 ) - - 1 (0 .8 % ) - - 1 (0 .9 ) - N eo m yc in s ul fa te 2 0. 0% p et 0/ 16 0 - - - - - - - - - - C ob al t ch lo ri de 1 .0 % p et 9/ 16 0 5. 6% 4 (5 .8 ) 5 (5 .5 ) >. 99 1 (2 .8 ) 8 (6 .5 ) .6 85 1 (1 .9 ) 8 (7 .5 ) .2 74 B en zo ca in e 10 .0 % p et 0/ 16 0 - - - - - - - - - N ic ke l s ul fa te 5 .0 % p et 17 /1 60 10 .6 % 2 (2 .9 ) 15 (1 6. 5) .0 08 5 (1 3. 9) 12 (9 .7 ) .5 39 4 (7 .5 ) 13 (1 2. 1) .4 29 C lio qu in ol 5 .0 % p et 0/ 93 - - - - - - - - - - C ol op ho ny 2 0. 0% p et 3/ 16 0 1. 9% 1 (1 .4 ) 2 (2 .2 ) >. 99 0 3 (2 .4 ) >. 99 2 (3 .8 ) 1 (0 .9 ) .2 55 Pa ra be n m ix 1 6. 0% p et 1/ 16 0 0. 6% 0 1 (1 .1 ) - 0 1 (0 .8 ) - 0 (0 ) 1 (0 .9 ) - N -I so pr op yl -N -p he ny l- 4- ph en yl en ed ia m in e 0. 1% p et 1/ 16 0 0. 6% 1 (1 .4 ) 0 - 0 1 (0 .8 ) - 1 (1 .9 ) 0 - L an ol in A lc oh ol 3 0. 0% p et 0/ 16 0 - - - - - - - - - - M er ca pt o m ix 2 .0 % p et 0/ 16 0 - - - - - - - - - E po xy r es in 1 .0 % p et 1/ 16 0 0. 6% 0 1 (1 .1 ) - 0 1 (0 .8 ) - 1 (1 .9 ) 0 (0 ) - M yr ox yl on p er ei ra e re si n 25 .0 % pe t 3/ 16 0 1. 9% 1 (1 .4 ) 2 (2 .2 ) >. 99 3 (8 .8 ) 0 .0 11 0 3 (2 .8 ) .5 55 4- Te rt -B ut yl ph en ol f or m al de hy de re si n 1. 0% p et 1/ 16 0 0. 6% 0 1 (1 .1 ) - 1 (2 .8 ) 0 - 0 1 (0 .9 ) - 2- M er ca pt ob en zo th ia zo le ( M B T ) 2. 0% p et 0/ 16 0 - - - - - - - - - - Fo rm al de hy de 2 .0 % a q 2/ 16 0 1. 3% 0 2 (2 .2 ) .5 06 0 2 (1 .6 ) >. 99 0 2 (1 .9 ) >. 99 4 Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 N u m b er o f p o si ti ve re ac ti o n s/ t o ta l n u m b er o f te st ed p at ie n ts Pr ev al en ce % (9 5% C I) Se x N (% ) P va lu e A to p ic D er m at it is N (% ) P va lu e A g e G ro u p N (% ) P va lu e B o y G ir l A D N o n -A D C h ild re n A d o le sc en t Fr ag ra nc e m ix I 8 .0 % p et 1/ 16 0 0. 6% 0 1 (1 .1 ) - 1 (2 .8 ) 0 - 0 1 (0 .9 ) - Se sq ui te rp en e L ac to ne m ix 0 .1 % p et 0/ 16 0 - - - - - - - - -- - Q ua te rn iu m 1 5 1. 0% p et 1/ 16 0 0. 6% 0 1 (1 .1 ) - 0 1 (0 .8 ) - 0 1 (0 .9 ) - Pr im in 0 .0 1% p et 0/ 93 - - - - - M et hy lc hl or oi so th ia zo lin on e/ m et hy lis ot hi az ol in on e (M C I/ M I) 0. 02 % a q 13 /1 60 10 .7 % 3 (4 .3 ) 10 (1 1) .1 53 4 (1 1. 1) 9 (7 .3 ) .4 91 4 (7 .5 ) 9 (8 .4 ) >. 99 B ud es on id e 0. 01 % p et 0/ 16 0 - - - - - - - - - - T ix oc or to l- 21 -p iv al at e 0. 1% p et 1/ 16 0 0. 6% 1 (1 .4 ) 0 - 0 1 (0 .8 ) - 1 (1 .9 ) 0 - M et hy ld ib ro m o gl ut ar on it ri le 0 .5 % pe t 3/ 16 0 1. 9% 0 3 (3 .3 ) .2 60 0 3 (2 .4 ) >. 99 0 3 (2 .8 ) .5 51 Fr ag ra nc e m ix I I 14 .0 % p et 3/ 16 0 1. 9% 1 (1 .4 ) 2 (2 .2 ) >. 99 0 3 (2 .4 ) >. 99 2 (3 .8 ) 1 (0 .9 ) .2 55 H yd ro xy is oh ex yl 3 -c yc lo he xe ne ca rb ox al de hy de 5 .0 % p et 0/ 16 0 - - - - - - - - - - M et hy lis ot hi az ol in on e 0. 2% a q 4/ 11 3 3. 5 % 1 (2 .2 ) 3 (4 .5 ) .6 45 1 (5 ) 3 (3 .2 ) .5 47 2 (5 .7 ) 2 (2 .6 ) .5 86 Te xt ile d ye m ix 6 .6 % p et 2/ 91 2. 1% 1 (6 .3 ) 1 (2 .8 ) .5 25 1 (8 .3 ) 1 (2 .5 ) .4 12 0 2 (5 .1 ) >. 99 2- H yd ro xy et hy l m et ha cr yl at e 2. 0% pe t 0/ 67 - - - Pr op ol is 1 0. 0% p et 0/ 67 - - - C I: C on fi de nc e in te rv al S ig ni fi ca nt r es ul ts ( P < 0. 05 ) ar e sh ow n in b ol d. Ta b le 1 . F re qu en cy o f co nt ac t se ns it iz at io n to E B S al le rg en s an d di st ri bu ti on s of p os it iv it y ac co rd in g to s ex , a to pi c de rm at it is , a nd a ge g ro up . ( co nt in ue d) Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 5 Turkey [7-10]. The frequency of nickel sensitivity in the pe- diatric population rises with age, the risk being significantly greater among girls [14]. Nickel allergy prevalences of 13% in girls with pierced ears compared to 1% in those without were reported in one study [15]. The prevalence of contact allergy to nickel sulfate in the present study was also sig- nificantly higher among girls (P=.008). Ear piercing in the first 2–3 years of life is a common tradition in Turkey, the holes being kept open by imitation or gold jewelry that may also contain nickel [7]. Turkish legislation limits nickel re- lease to 0.5 µg/cm²/week in items intended for direct con- tact with the skin [16]. The regulation was fully enforced by the end of 2021, and positive effects on metal sensitivity are anticipated. Cobalt chloride was another common metal allergen with a 5.6% sensitivity rate and significantly higher in our patients with a positive response to nickel sulfate (P=.008). Positive patch test reactions to cobalt chloride in the pe- diatric age group ranged between 4.4% and 11.1% [13]. Concomitant nickel and cobalt sensitization may be a result of cross-sensitivity due to the similar atomic structures, or dual sensitization may result after separate or coupled expo- sure to nickel and cobalt [17]. Preservatives constituted two of the five principal al- lergens in this study (MCI/MI 8.1%, and MI 3.5%). MCI/ MI and MI are isothiazolinone preservatives frequently employed as skin care agents for babies and children as well in cosmetics, household products or water-based paints, glues, and slime. MCI/MI sensitivity rates in children in previous studies ranged from 2.4% in asymptomatic infants to 11.7% in children referred for patch testing [18,19]. Zafrir et al.’s re- view of 48 studies reported that MCI/MI was not among the five most common allergens in children; however, it has been identified as one of the most common allergens in Turkish children, with 12%–20% sensitivity rates [6,8,10]. Yılmaz et al. reported a low sensitivity rate of MCI/MI (1.9%), but also stressed that the number of patients with MCI/ MI-induced ACD rose five-fold in 1996–2006 compared to 2007–2017 [9]. The sensitivity rate of MI in the present study was 3.5%. Turkish cosmetic regulations permit MCI/MI to be used in rinse-off products at a maximum concentration of 15 ppm, while MI can be employed at up to 100 ppm [20]. The presence of MCI/MI and MI in leave-on prod- ucts in Turkey until 2015 and 2017, respectively, may have caused the high sensitivity rates in our study. Sensitivity to MCI/MI and MI is a major public health problem in Turkey, and regulations are needed to reduce the permitted level of MI in rinse-off cosmetics. PPD is a significant component of chemical hair dyes and black henna tattoos. In the present study, the contact sensi- tivity of PPD was 5%, and ranged from 7.1% to 9.5% in other studies from Turkey. These results are slightly higher in girls (P=0.034). The prevalence of contact allergy to nickel sulfate was significantly higher in girls than in boys (2.9% vs 16.5%) (P=.008). However, there was no signifi- cant association between positive reactions to other allergens and sex (P>.05). The mean age of the patients with contact sensitivity to EBS allergens was 12.7±4.2 years. No significant association was found between age and patch test positivity (P=.496). Contact sensitivity to at least one allergen was observed in 28.3% (n=15) of the children and 31.8% (n=34) of the ad- olescents, although the difference was not statistically sig- nificant (P=.654). There was also no significant association between the distribution of contact sensitivity rates to each EBS allergen and age groups (P> .05). Positive reactions to at least one allergen were deter- mined in 29.4% (n=15) of individuals with a personal his- tory of atopy and in 33.3% (n=12) of those diagnosed with AD. No significant difference in positive patch test rates was observed between patients with and without atopy (P>.05). The presence of AD also exhibited no significant effect on contact sensitivity rates (P>.05). However, contact sensitivity to Myroxylon pereirae resin was significantly higher in pa- tients with atopy (P=0.031) and AD (P=.011), and a signifi- cant relationship was observed between contact sensitivity to fragrance allergens and individuals with AD (P=.046). Conclusions The frequency of positive reactions to EBS allergens in Turk- ish children and adolescents in this study was 30.6%. Five studies from Turkey reported patch test positivity in 32% to 57.5% of children [6-10]. Zafrir et al. reviewed 50  series from 48 studies from Europe, North America, South Amer- ica, and Asia. Patch test reaction positivity in children ranged from 14.5% to 70.7% in Europe, 61% to 95.6% in North America, and 45.4% to 80% in Asia [13]. Our result is con- sistent with some European studies involving EBS allergens, but substantially lower than in the North American studies, which report high sensitization rates. In contrast to contact sensitivity rates, the most common allergens do not differ significantly. Zafrir et al. reported nickel sulfate as the most common allergen, followed by cobalt nitrate, thimerosal, fragrance mix, and potassium dichromate in 48 different international studies [13]. The five most common allergens in the present study were nickel sulfate (n=17, 10.6%), MCI/MI (n=13, 8.1%), cobalt chloride (n=9, 5.6%), p- phenylenediamine (PPD) (n=8, 5%), and MI (n=4, 3.5%). The prevalence of pediatric nickel-induced ACD in pre- vious studies ranged between 6.8% and 80.4% [13]. The prevalence of contact sensitization to nickel sulfate among Turkish children varied between 7.2% and 46%, and nickel sulfate is also the most common allergen in studies from 6 Original Article | Dermatol Pract Concept. 2024;14(2):e2024151 systematic review and meta-analysis. Contact Dermatitis. May 2011;64(5):245-57. doi:10.1111/j.1600-0536.2010.01860.x 4. Smith VM, Clark SM, Wilkinson M. Allergic contact dermati- tis in children: trends in allergens, 10 years on. A retrospective study of 500 children tested between 2005 and 2014 in one UK centre. Contact Dermatitis. Jan 2016;74(1):37-43. doi:10.1111 /cod.12489 5. Admani S, Jacob SE. Allergic contact dermatitis in children: review of the past decade. Curr Allergy Asthma Rep. Apr 2014; 14(4):421. doi:10.1007/s11882-014-0421-0 6. Kundak S. Patch Test Results of Contact Sensitization in Chil- dren Without Atopic Dermatitis: A Single Tertiary Center Expe- rience. Dermatitis. Mar/Apr 2020;31(2):153-156. doi:10.1097 /DER.0000000000000530 7. Onder M, Adisen E. Patch test results in a Turkish paediat- ric population. Contact Dermatitis. Jan 2008;58(1):63-5. doi:10.1111/j.1600-0536.2007.01171.x 8. Akan A, Toyran M, Vezir E, et al. The patterns and clinical rele- vance of contact allergen sensitization in a pediatric population with atopic dermatitis. Turk J Med Sci. 2015;45(6):1207-13. doi:10.3906/sag-1309-62 9. Yilmaz Z, Ozkaya E. Patch-test results in terms of the recently recommended allergens in children and adolescents: A retrospec- tive cohort study over 22 years from Turkey. Contact Dermatitis. Mar 23 2021;doi:10.1111/cod.13842 10. Yucel E, Ozceker D. Contact allergen sensitivity in children with contact dermatitis. Turk Arch Pediatr. Jan 2021;56(1):51-56. doi:10.14744/TurkPediatriArs.2020.79577 11. Wahlber J. Patch testing. In: Raycroft RJG MT, Frosch PJ, et al. eds., ed. 3rd ed. Springer-Verlag; 2001:439-468. 12. Hanifin JMR, G. Diagnostic futures of atopic dermatitis. Acta Derm Venereol. 1980;Suppl(92):44-47. 13. Zafrir Y, Trattner A, Hodak E, Eldar O, Lapidoth M, Ben Amitai D. Patch testing in Israeli children with suspected allergic contact dermatitis: A retrospective study and literature review. Pediatr Dermatol. Jan 2018;35(1):76-86. doi:10.1111/pde.13333 14. Warshaw EM, Aschenbeck KA, DeKoven JG, et al. Epidemiol- ogy of pediatric nickel sensitivity: Retrospective review of North American Contact Dermatitis Group (NACDG) data 1994-2014. J Am Acad Dermatol. Oct 2018;79(4):664-671. doi:10.1016/j. jaad.2018.02.071 15. Larsson-Stymne B, Widstrom L. Ear piercing--a cause of nickel allergy in schoolgirls? Contact Dermatitis. 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Guidelines for the use of preservatives than in other studies from the literature, which reported 3.5% and 4.2% contact sensitivity rates to PPD [21]. Tem- porary tattoos containing high concentrations of PPD con- stitute a major cause of sensitivity in Turkish children and adolescents. The question of whether children with AD are particu- larly prone to allergic contact dermatitis (ACD) is controver- sial. A systematic review and meta-analysis reported similar prevalences of contact sensitization in individuals with and without AD, recommending that clinicians should consider patch testing on suspicion of ACD [22]. In a review of 21 studies comparing the patch test results of children with and without AD, the prevalence of contact allergy was significantly higher among children without AD (overall, 41.7% vs 46.6%) [23]. Patch testing may be useful as a screening tool in the management of pediatric AD. It should always be considered in recalcitrant AD or if ACD is indi- cated by a previous medical history [23]. The allergens to which children with AD react differ significantly from those in children without AD. All children with AD are inevitably chronically exposed to topical agents, and epidermal barrier defects in AD may facilitate sensitization to medications and fragrances. In this study, the contact sensitivity rate to My- roxylon pereirae resin was significantly higher in patients with AD (P=.011), and a significant relationship was found between the fragrance allergens group and patients with AD (P=.046). A study of 1012 Dutch children reported that indi- viduals with AD reacted significantly more frequently to fra- grances (fragrance mix I and Myroxylon pereirae resin) [24]. Personal care products containing fragrances should also be considered as potential causes of ACD in children, especially those with AD. A recent study found that 89% of 187 sur- veyed products labeled as “hypoallergenic,” “dermatologist recommended/tested,” “fragrance-free,” or “paraben-free” contained at least one contact allergen [25]. In conclusion, metals and preservatives are the main al- lergens in Turkish children. Legislation that was enacted in 2022 would lower the high nickel sensitivity rates. However, regulations are required to reduce the permitted level of MI in rinse-off cosmetics. The principal limitation of this study is that the clinical relevance of allergens was not investigated. References 1. Veien NK, Hattel T, Justesen O, Norholm A. Contact derma- titis in children. Contact Dermatitis. Nov 1982;8(6):373-5. doi:10.1111/j.1600-0536.1982.tb04261.x 2. Simonsen AB, Deleuran M, Johansen JD, Sommerlund M. Con- tact allergy and allergic contact dermatitis in children - a review of current data. Contact Dermatitis. Nov 2011;65(5):254-65. doi:10.1111/j.1600-0536.2011.01963.x 3. 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Allergic contact dermatitis in Danish children referred for patch testing - a nationwide multicentre study. Con- tact Dermatitis. Feb 2014;70(2):104-11. doi:10.1111/cod.12129 22. Hamann CR, Hamann D, Egeberg A, Johansen JD, Silverberg J, Thyssen JP. Association between atopic dermatitis and con- tact sensitization: A systematic review and meta-analysis. J Am Acad Dermatol. Jul 2017;77(1):70-78. doi:10.1016/j.jaad.2017 .02.001 23. Simonsen AB, Johansen JD, Deleuran M, Mortz CG, Sommerlund M. Contact allergy in children with atopic dermatitis: