ESCD Abstracts: Posters

Transcription

1 Contact Dermatitis Abstract COD Contact Dermatitis ESCD Abstracts: Posters P001 Autoxidized limonene as a contact hapten: a multicentre prospective study of contact sensitization to hydroperoxides of limonene in Spain G. Deza, 1 L, García-Colmenero, 1 F. Heras, 2 J. Sanchez, 3 J.F. Silvestre, 4 L. Borrego, 5 J. Ortiz, 6 V. Fernandez, 7 R. Gonzalez, 8 J.M. Carrascosa, 9 B. García-Bravo, 10 I. Ruiz, 11 S. Córdoba, 12 B. Niklasson 13 and A.M. Giménez-Arnau 1 1 Hospital del Mar Institut Mar d Investigacions Mèdiques, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; 2 Hospital del Sureste, Madrid, Spain; 3 Hospital La Princesa, Madrid, Spain; 4 Hospital General de Alicante, Valencia, Spain; 5 Hospital Insular Las Palmas, Las Palmas Gran Canarias, Spain; 6 Hospital 12 Octubre, Madrid, Spain; 7 Hospital Gil Casares, Santiago de Compostela, Spain; 8 Hospital Universitaria Araba, Vitoria, Spain; 9 Hospital Germans Trias i Pujol, Badalona, Spain; 10 Hospital Virgen de la Macarena, Sevilla, Spain; 11 Complejo Universitario de León, Castilla y León, Spain; 12 Hospital Universitario Fuenlabrada, Madrid, Spain and 13 Chemotechnique Diagnostics, Vellinge, Sweden Limonene is a common fragrance terpene found in domestic and industrial products. Limonene autoxidizes upon exposure to air and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% of 2900 patients had a positive patch test reaction to oxidized R-limonene 3.0% [containing limonene hydroperoxides 0.33% in petrolatum (pet.)]. Patch testing to this compound is not routinely carried out in Spain or other European countries. Our objective was to investigate the frequencies of reaction to patch test material using limonene hydroperoxides and the differences in the reaction pattern at three different concentrations [0.1%, 0.2% and 0.3% pet. (regular recommended concentration)] in the Spanish population. Between April 2015 and February 2016, 3639 consecutive patients were patch tested with limonene hydroperoxides at 0.1, 0.2 and 0.3% pet. using IQ Ultimate chambers (Chemotechnique, Vellinge, Sweden) in 22 Spanish dermatology departments. A total of 256 patients (256/3639; 7.0%) showed some reaction to oxidized R-Limonene. Of these 256 patients, 187 (73.0%) were female, 62 (24.2%) had a personal history of atopy, 39 (15.2%) showed occupational relevance and mean age was 46.1 years. A total of 187 patients [187/3639; 5.1% (range %)] had an allergic patch test reaction to hydroperoxides of limonene 0.3% pet., while 124 (3.4%) and 51 (1.4%) patients had this reaction at 0.2% and 0.1% pet., respectively. Doubtful reactions were found in 25 (0.7%), 21 (0.6%) and 14 (0.4%) patients tested with hydroperoxides of limonene at 0.1, 0.2 and 0.3% pet., respectively. Irritant reactions were found in 11 (0.3%), 30 (0.8%) and 55 (1.5%) patients tested with hydroperoxides of limonene at 0.1, 0.2 and 0.3% pet., respectively. The high rate of positive patch test reactions to oxidized R-limonene found in this large multicentre Spanish study, in accordance with similar European studies, supports the recommendation to include limonene in its oxidized form in the baseline patch test series. Despite the high number of irritant reactions found, in this study the optimum concentration with which to test hydroperoxides of limonene seems to be 0.3% pet., as with this concentration a higher number of allergic patients could be detected. P002 Orofacial granulomatosis associated with delayed hypersensitivity to acrylates present in dental prosthesis A. Teixeira, M. Camacho, L. Soares-Almeida and T. Correia Hospital de Santa Maria, Lisbon, Portugal Orofacial granulomatosis (OFG) is a clinicopathological entity characterized by persistent swelling of the face, lip or oral tissues in the presence of noncaseating granulomas in biopsy specimens. The spectrum of OFG includes Melkerson Rosenthal syndrome, Miescher syndrome and granulomatous cheilitis. This descriptive term lacks specificity, and some authors consider it to also describe oral manifestations of Crohn disease, sarcoidosis or tuberculosis. Although the cause of OFG remains unclear, delayed hypersensitive reactions are thought to play a significant role, with few authors reporting the association of OFG with contact sensitivity to food additives, flavourings and dental restorative materials. We discuss the case of a patient with OFG induced by contact allergy to 2-hydroxyethylmethacrylate and ethylene glycol dimethacrylate present in dental prosthesis. A 53-year-old white woman presented to us with asymptomatic erythema and swelling of the lower lip, and swelling of the tongue present for the past 11 months. She had a history of thymoma resection 2 years previously, and was not currently taking any medication. The patient regularly used a dental prosthesis owing to multiple missing teeth in the inferior arcade. A skin biopsy of the inferior lip revealed the presence of intradermal noncaseating granulomas and subepithelial lymphocyte infiltrate. Ziehl Neelsen and periodic acid Schiff stains did not show acid-fast bacilli or fungi, and polarizable foreign bodies were not detected. Laboratory investigations (complete blood count, erythrocyte sedimentation rate, serum angiotensin-converting enzyme) and imaging studies (oral magnetic resonance, chest radiography, colonoscopy) excluded Crohn disease, sarcoidosis and focal infections. Hereditary angioedema and food allergy were excluded by normal prick tests and specific IgE levels. Patch tests revealed delayed hypersensitivity to 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate. The patient was treated with systemic corticosteroids and advised to discontinue the use of the prosthesis, which resulted in resolution of the oedema. Allergic contact granulomatous reactions are rarely seen in clinical practice and are most frequently described in association with metals (beryllium, aluminium, zirconium, etc.). Acrylates are potent sensitizers frequently causing occupational dermatosis. However, there are reports connecting delayed hypersensitivity to acrylates with dental prosthesis intolerance clinically manifested by cheilitis and perioral dermatitis, burning mouth syndrome and lichenoid reactions. In 60 Contact Dermatitis, 75 (Suppl. 1),

2 this case, the positive results of patch tests with 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate, together with the clinical resolution following prosthesis discontinuation, suggests that an immunological mechanism of delayed hypersensitivity was involved in the granuloma formation, allowing us to postulate that the OFG seen in our patient is an expression of a granulomatous contact allergic reaction. P003 Is unsubstituted benzophenone a potential screening agent to detect photocontact allergy to octocrylene? O. Aerts, 1 Y.Y. Kong, 1 J. Leysen, 1 W. De Borggraeve, 2 J. Lambert 1 and A. Goossens 3 1 University Hospital Antwerp, Dermatology, Antwerp, Belgium, 2 KU Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, Leuven, Belgium and 3 University Hospitals KU Leuven, Dermatology, Leuven, Belgium Octocrylene can be prepared by a condensation reaction involving benzophenone. Photopatch testing octocrylene samples obtained from cosmetic companies may be more reliable than using commercialized patch test materials, raising the question of whether impurities may be the actual allergens. The objectives were to report two patients with photo-(aggravated) contact allergy to octocrylene and to discuss the work-up performed in both patients. Two male patients, following the application of a topical ketoprofen-containing gel and sun-protecting creams containing octocrylene, respectively, presented with vesicular skin eruptions following ultraviolet (UV) exposure. In both patients, a baseline series, a cosmetic series and (in duplicate) a photopatch test series [also containing three samples of octocrylene 10% in petrolatum obtained from the cosmetic industry (OCT*) and unsubstituted benzophenone (UB) 1% and 5% (in-house preparations)] were tested. In patient 1, two different batches of octocrylene (OCT-A and OCT-B), from Chemotechnique (Vellinge, Sweden), were additionally photopatch tested. Following an occlusion of 2 days, one of both photopatch test series was irradiated with 5J UVA, and readings were performed on days 2, 3 and 7 following application of the tests. In patient 1, ketoprofen and etofenamate produced strong (++) photopatch test reactions, while OCT reacted only doubtfully (?), on day 3. OCT-A and OCT-B became positive (+) at the irradiated side on day 3, and remained so on day 7. The three OCT* samples reacted more strongly (+ to ++), on days 3 and 7, only at the irradiated side. A photopatch test with benzophenone-10 also became positive (+) on day 7, while irradiated UB 1% and 5% were already strongly positive (+++) on day 3 and remained so on day 7, with even the nonirradiated side becoming positive (+) on day 7. In patient 2, the patch test with OCT was positive (+) on day 3, while the photopatch test was only doubtful (?). The three OCT* samples were positive (+) on day 3, and even more so following irradiation (++), which was still visible (+) at day 7. UB 1% and 5% produced reactions on days 3 (+) and7(++) attheirradiated side with the nonirradiated side also showing a reaction (+), but only at day 7. Irradiated ketoprofen became positive (++)onday7. To detect photoreactivity to octocrylene, photopatch testing several batches of the commercial patch test material, samples obtained from the cosmetic industry and/or unsubstituted benzophenone may be of interest. It remains to be shown whether residual benzophenone impurities in octocrylene test materials might explain our observations. P004 Contact allergy to methyldibromoglutaronitrile preservative: European Surveillance System on Contact Allergies results from the baseline series, A.M. Giménez-Arnau, 1 G. Deza, 1 A. Bauer, 2 G. Johnston, 3 V. Mahler, 4 M.-L. Schuttelaar, 5 J. Sanchez, 6 J.F. Silvestre, 7 M. Wilkinson 8 and W. Uter 9 1 Department of Dermatology, Hospital del Mar, Universitat Autónoma, Barcelona, Spain; 2 Department of Dermatology, University Allergy Centre, University Hospital Carl Gustav Carus Technical University, Dresden, Germany; 3 Department of Dermatology, Leicester Royal Infirmary, Leicester, U.K.; 4 Department of Dermatology, University Hospital Erlangen, Erlangen, Germany; 5 Department of Dermatology, University Medical Center, Groningen, the Netherlands; 6 Department of Dermatology. Hospital Universitario de la Princesa, Madrid, Spain; 7 Servicio de Dermatología, Hospital General Universitario, Alicante, Spain; 8 Department of Dermatology, Chapel Allerton Hospital, Leeds, U.K.; and 9 Department of Medical Informatics, Biometry and Epidemiology, University Erlangen-Nürnberg,, Erlangen, Germany The preservative methyldibromoglutaronitrile (MDBGN) was approved for cosmetic use in 1986 at a maximum concentration of 0.1% in both leave-on and rinse-off products. In reports from 16 European centres, rates of sensitization increased from 0.7% in 1991 to 3.5% in In the U.S.A., sensitivity rates rose to 11.7%. In 2005, the European Union (EU) banned its use in leave-on, and in 2007 also in rinse-off, products. Nevertheless, MDBGN is still sensitizing patients. Our objective was to assess the prevalence of contact allergy to MDBGN diagnosed by patch testing following its ban by the EU. A retrospective analysis was performed on data collected by the European Surveillance System on Contact Allergies ( network. The study period was from January 2009 to December 2012 and included 54 departments from 12 European countries. Altogether consultations involved application of the baseline series. The biocide allergens contained in the European Baseline Series (EBS) were tested in consecutive patients. MDBGN was tested at 0.2%, 0.3% and 0.5% in petrolatum (pet.). Usage across the different departments differed significantly between the years (P < 0.01, test), with 0.2% pet. constant at 23% (2009) to 27% ( ) of all tests, 0.3% pet. decreasing in usage from 60% in 2009 to 47% in 2012, and 0.5% pet. increasing from 16% in 2009 to 26% in The prevalence of positive patch tests to MDBGN was 2.8%, 2.7% and 2.5% at concentrations of 0.2% pet., 0.3% pet. and 0.5% pet., respectively. When stratified for age group, the percentage of positive reactions was 3.7%, 2.6% and 3.0% in those older than 64 years of age; 2.9%, 1.6% and 2.5% in those aged years; and 1.8%, 0.5% and 0.7% in those younger than 16 years of age at MDBGN concentrations of 0.25 pet., 0.3% pet. and 0.5% pet., respectively. The pooled results from all three concentrations, interpreted with some caution, show an upward trend, except in the youngest age group, where the prevalence of sensitization remained constant. The upward trend in the middle Contact Dermatitis, 75 (Suppl. 1),

3 and older age groups were statistically significant in a bivariate test for trend (P < 0.01) and remained significant in a log binomial regression analysis adjusted for test concentration, sex and country in these two subgroups. Although a significant decrease in the prevalence of positive patch tests to MDBGN was observed (4% to 3% from 2004 to 2008), contact allergy to MDBGN still occurs and so we recommend this allergen remains in the EBS. P005 Cutaneous allergy testing in anogenital dermatoses C.C. Foley, S. White, S. Merry, U. Nolan, B. Moriarty, P. Collins, B. Kirby and A. Lally St Vincent s University Hospital, Dublin, Ireland Many patients with anogenital dermatoses are exposed to contact allergens from personal care products and over-the-counter topical treatments prior to consulting a dermatologist. Cutaneous allergy testing may be a useful investigation in this patient group. The aim of this study was to identify the common allergens detected on cutaneous allergy testing in patients presenting with anogenital dermatoses. Patients with perianal and/or genital symptoms who underwent cutaneous allergy testing between January 2013 and December 2015 were reviewed (n = 99). Fifty-seven patients (mean ± SD age 48.0 ± 16.7 years; mean ± SD duration of symptoms 5.5 ± 7.1 years) were included: 17 females with perianal symptoms alone, 23 females with isolated genital symptoms and 19 females with anogenital symptoms. The series tested included the British Society for Cutaneous Allergy standard series in all 99 patients, cosmetic/facial in 33, medicament in 68, fragrances/essential oils in 63, textiles/colours/finishes in 34, corticosteroid in eight, Caine mix breakdown in 10 and own products in 11. Allergic reaction to allergens was identified in 69 of 99 patients (70%), with 33 of 69 (48%) considered relevant to the presenting complaint, 31 of 69 (45%) of uncertain relevance and five of 69 (7%) of past relevance. In patients with currently relevant contact allergens, 21 of 33 (64%) had perianal symptoms, five of 33 (15%) had genital symptoms and seven of 33 (21%) had combined anogenital symptoms at presentation. The most common currently relevant contact allergens in this group were Balsam of Peru (12/33; 36%), Caine mix III (nine of 33; 27%) and fragrance mix I (seven of 33; 21%), suggesting that patients are using products in the anogenital area for symptoms of another dermatosis prior to developing allergic contact dermatitis. Follow-up data were available for 24 of 33 patients with relevant allergens, of whom 13 (54%) reported improvement before cutaneous allergy testing, nine (38%) following testing and two (8%) reported no improvement. In patients with no relevant contact allergen who attended follow-up appointment (51 of 66), 28 of 51 (55%) improved before patch testing, 14 of 51 (27%) following testing and nine of 51 (18%) had no improvement. There is a paucity of published data on cutaneous allergy testing for anogenital dermatoses. One-third of our cohort had a relevant contact allergen identified. The most commonly identified relevant allergens in this study were those present in over-the-counter cleansing and haemorrhoid preparations. Importantly, 55% of our patients reported an improvement in symptoms with topical corticosteroids and skincare advice alone. This study re-emphasizes the importance of skincare advice and avoidance of known allergens and irritants in the management of anogenital dermatoses. P006 Allergic contact dermatitis caused by (meth)acrylates in users and technicians of artificial nails: a 5-year study I. Raposo, 1 I. Lobo, 1 C. Amaro, 2 M. de Lurdes Lobo, 2 H. Melo, 3 J. Parente, 4 T. Pereira, 5 J. Rocha, 6 P. Serrano, 7 T. Correia, 8 M. Dias, 9 A.R. Travassos, 3,8 F. Pereira 10 and M. Gonçalo 11 1 Dermatology Department, Centro Hospitalar do Porto, Porto, Portugal; 2 Dermatology Department, Centro Hospitalar Lisboa Central, Lisbon, Portugal; 3 Dermatology Department, Hospital CUF Descobertas, Lisbon, Portugal; 4 Dermatology Department, Hospital de Santarém, Santarém, Portugal; 5 Dermatology Department, Hospital de Braga, Braga, Portugal; 6 Dermatology Department, Hospital Pedro Hispano, Matosinhos, Portugal; 7 Dermatology Department, Hospital Garcia da Orta, Almada, Portugal; 8 Dermatology Department, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal; 9 Dermatology Department, Hospital Egas Moniz, Centro Hospitalar Lisboa Oriental, Lisbon, Portugal; 10 Dermatology Department, Hospital CUF Infante Santo, Lisbon, Portugal; and 11 Clinic of Dermatology, University Hospital and Faculty of Medicine, University of Coimbra, Coimbra, Portugal In the last few years, with the more common use of artificial nails, an increasing number of cases of allergic contact dermatitis (ACD) caused by (meth)acrylates have been reported. The aim of the present study was to provide information of ACD caused by (meth)acrylates in relation to artificial nails. In a retrospective study, we reviewed the files of patients with ACD caused by (meth)acrylates from artificial nails who were patch tested between January 2011 and December 2015 at 11 departments of occupational and environmental dermatology in Portugal. All patients were tested with the Portuguese and European Baseline Series and an extended series of (meth)acrylates. We detected 197 cases of ACD to (meth)acrylates (55 technicians, 55 customers, and 87 both technicians and customers). All patients were women (mean age 37 years; range 20 65). In 181 (92%) women, the manifestation was chronic hand eczema with fissured pulpitis in 148, but nail dystrophy only affected 37. Ectopic lesions on the face were detected in 61 cases (31%).The most common sensitizers among the 197 allergic individuals were 2-hydroxyethyl methacrylate [HEMA; positive in 173 cases (92% of the 188 patch tested patients], 2-hydroxypropyl methacrylate [HPMA; positive in 96 patients (62% of 155 tested patients)] and ethyleneglycol dimethacrylate [positive in 95 patients (50% out of the 189 tested)]. HEMA and HPMA were the most frequent positive allergens and, in agreement with previous studies, HEMA with > 90% of positive tests can be considered a good screening allergen. We stress the high number of cases of ACD from (meth)acrylates in relation to artificial nails, both in consumers and nail technicians, certainly deserving better preventive measures at the occupational level and specific regulation from the authorities concerned with the safety of consumers. 62 Contact Dermatitis, 75 (Suppl. 1),

4 P007 Immediate reactions in hand eczema J. Azevedo, 1 F. Regateiro, 2 M. Gouveia, 3 L, Ramos 3 and M. Gonçalo 4 1 Clinic of Immunoallergology and 3 Clinic of Dermatology, University Hospital Center of Coimbra, Coimbra, Portugal; 2 Clinic of Immunoallergology and 4 Clinic of Dermatology, University Hospital and Faculty of Medicine, University of Coimbra, Coimbra, Portugal Hand eczema (HE) is a multifactorial disease often coexisting with atopic hand dermatitis, irritant contact dermatitis, allergic contact dermatitis (T-cell mediated) and immediate symptoms (contact urticaria and/or protein contact dermatitis), dependent or not on IgE. The aim was to characterize patients with HE who reported immediate symptoms on handling suspected triggers. We retrospectively analysed the files of patients with HE who had both patch and skin prick testing (SPT) done between 2007 and Patch testing (PT) was performed according to European Contact Dermatitis Society guidelines with the baseline and complementary series selected according to the clinical history. SPT was performed whenever patients complained of immediate symptoms. Allergens used for immediate testing were latex (Bial-Aristegui) and mostly fresh foods (prick-by-prick). SPT with a 3-mm weal or larger than the negative control were considered positive. In some patients, total and specific IgE levels were also evaluated. We evaluated 52 patients (49 women, three men), aged years (mean ± SD age 33.4 ± 9.9), with a duration of HE of 6 months to 20 years (mean ± SD 4.1 ± 3.5), 25 (48%) with a personal history of atopy (nine with atopic dermatitis). Dermatitis was occupational in 33 patients (64%) and, apart from HE, it also involved the face in six patients (11%). Positive PT were observed in 31 patients (60%), mostly to nickel (14 27%). Positive SPT were observed in 28 patients (54%), four ofr nine (44%) with atopic dermatitis. Positive reactions were observed mainly to fruits and vegetables [12 patients (kiwi, n = 8; tomato, n = 4; potato, n = 4 each)], latex (n = 10), fish (n = 3), molluscs and crustaceans (n = 3) and flour (n = 3). Specific IgE was positive in 11 of 33 tested patients, all in agreement with positive SPT. There was no correlation between positive SPT and atopy or high serum IgE. Although this study includes a limited number of patients with HE and we performed SPT only in those with a positive history, we observed immediate reactions in a very significant percentage of the tested patients (54%). Specific IgE was of no use for further diagnosis. The contribution of immediate, non-tcell-dependent mechanisms may be significantly involved in the pathogenesis of HE and therefore immediate testing should be considered, apart from the patch testing technique, in the study of HE. P008 Investigation of two diisocyanates and their corresponding amines for sensitizing capacity and cross-reactivity in the guinea pig H. Hamada, M. Engfeldt, M. Isaksson, M. Bruze and E. Zimersson Department of Occupational and Environmental Dermatology, Lund University, Malmö, Sweden Isocyanates together with polyols are used in the production of polyurethane polymers, plastics and rubbers. Dermal exposure to isocyanates can induce contact allergy. The most common isocyanate is diphenylmethane diisocyanate (MDI). The MDI isomer 4,4 -diphenylmethane diisocyanate (4,4 -MDI) is used in patch testing. It is unstable in patch test preparations and may cause false-negative patch tests. 4,4 -Diaminodiphenylmethane (4,4 -MDA) is the corresponding amine to 4,4 -MDI. In the literature, several reports describing concurrent reactions to 4,4 -MDI and 4,4 -MDA can be found, and often 4,4 -MDA allergy has been considered to be an indication of MDI allergy. Furthermore, concurrent reactions of 4,4 -MDI and dicyclohexylmethane-4,4 -diisocyanate (4,4 -DMDI) have been reported. The objective was to investigate the sensitization capacities and the cross-reactivity of 4,4 -MDI, 4,4 -MDA, 4,4 -DMDI and 4,4 -diaminodicyclohexylmethane (4,4 -DMDA). The guinea pig maximization test (GPMT) was used with nonirritating and, when possible, equimolar concentrations of the test substances for induction and challenge. The GPMT showed sensitizing capacities for all investigated substances: 4,4 -MDI (P = 0.02), 4,4 -MDA (P < 0.01), 4,4 -DMDI (P < 0.01) and 4,4 -DMDA (P = 0.06). 4,4 -MDI-sensitized animals showed cross-reactivity to 4,4 -MDA (P < 0.01) and 4,4 -DMDI (P = 0.02). 4,4 -MDA-sensitized animals showed cross-reactivity to 4,4 -DMDA (P = 0.01) and an indicated cross-reactivity to 4,4 -DMDI (P = 0.14). Animals sensitizedto4,4 -DMDI and 4,4 -DMDA did not show any cross-reactivity. All the investigated substances can be considered strong sensitizers. The background for the simultaneous 4,4 -MDI and 4,4 -MDA patch test reactions can be cross-reactivity with primary sensitization to 4,4 -MDI. The aromatic amine 4,4 -MDA can induce cross-reactivity to the aliphatic amine 4,4 -DMDA. P009 Contact allergy to beeswax in patients with cheilitis G. Nyman, 1 M. Tang, 2 A. Inerot 2 and L. Hagvall 2 1 Hudläkarmottagningen Telegrafen, Borås, Sweden and 2 Department of Dermatology, Sahlgrenska Academy, Göteborg, Sweden We have noticed that beeswax can cause contact allergy and cheilitis, but it is unknown what components of the wax are responsible for this. It is known that propolis, a lipophilic resinous substance manufactured by bees from living plants for gluing and sealing cracks in the bee hive, can occur as an impurity in beeswax and also can cause contact allergy. Caffeic acid and esters from this are known allergens in propolis. Earlier studies have not shown any clear relation between contact allergy to beeswax and propolis, and it is unclear if the same substances in the products are the cause of the allergy. From August 2009 until March 2016 we tested a cohort of patients suspected of having contact allergic cheilitis, eczema around the lips or contact allergy to products containing beeswax. The cohort consisted of 94 patients (85 women, nine men). Test material included yellow beeswax (cera flava) as is, white beeswax (cera alba) as is and propolis 10% in petrolatum. Fifteen patients had a positive patch test (12 women, three men) to either beeswax or propolis (16%) The patients with positive patch tests were contacted for retesting with caffeic acid, caffeic acid phenethyl ester and caffeic acid dimethylallyl ester in different concentrations. Twelve accepted and three did not (for practical reasons). Four of the tested patients had positive patch test results, all of whom had reacted to propolis. Contact allergy to beeswax seems to be common among patients with cheilitis, eczema around the lips or adverse reactions to products containing beeswax. Contact Dermatitis, 75 (Suppl. 1),

5 Propolis, alone or with beeswax, sometimes also give positive patch test reactions among those patients. It seems that caffeic acid and its esters are not important haptens, causing allergy in beeswax; however, they might be so in regard to contact allergy to propolis. Still, it has to be shown what causes haptens in beeswax and what the relation between contact allergy to propolis and beeswax is. P010 A novel barrier cream is effective in preventing allergic contact dermatitis from nickel-releasing items B. Niklasson, 1 A. Gregorius 2 and R. Spiewak 2 1 Department of Occupational and Environmental Dermatology, Skåne University Hospital, Lund University, Malmö, Sweden and 2 Department of Experimental Dermatology and Cosmetology, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland The aim was to assess the effectiveness of a barrier cream (NIK-L-BLOK ; Chemotechnique, Vellinge, Sweden) containing a strong nickel chelator, diethylenetriaminepentaacetic acid (DTPA), in the prevention of elicitation of dermatitis in nickel-sensitized patients. Two female, nickel-positive volunteers participated in this trial (+++ in IQ Ultra Chambers; Chemotechnique). Personal items that previously caused unequivocal eczema in the contact site on at least three different occasions were collected. Patient V1 presented with a belt buckle and earrings, and patient V2 with ear clips. All items were dimethylglyoxime-positive (Chemo Nickel Test ; Chemotechnique). In the reference phase, the volunteers wore the offending objects for approximately 4 h each day until the development of an eczematous reaction. When eczema appeared, the exposure was stopped. Time lapse from exposure to first symptoms (T prov ) was recorded. After corticosteroid treatment and an additional 2-week washout period, the second phase of the study was initiated in which the barrier cream was applied on the exposed sites three times daily after washing of the treated area. During this period, the volunteers wore the offending items as previously. For earrings, the barrier cream was richly applied on the earring post by dipping it in the cream. The observation lasted T prov + 4 weeks. V1 developed earlobe dermatitis to the earrings overnight and to the belt buckle on the stomach within 2 days. In the barrier phase, earlobe dermatitis developed after 2 days of wearing the barrier cream-dipped earrings; the same result was obtained on two different occasions. On the belt buckle-exposed area, the first signs of eczematous reaction and pruritus developed after 21 days and exposure to the buckle was ceased and steroid treatment cleared the symptoms within 4 days. The DTPA chelator, in a special formulation that immobilizes nickel ions (plus cobalt and chromium), appeared fully effective in the case of ear clips, and quite effective in case of the belt buckle (prolongation of the period of tolerance by a factor of 10.5). For earrings, the barrier cream, although prolonging the time lapse to first symptoms, did not appear as effective as the other uses, most likely down to too little cream penetrating into the pierced channel. P011 The reproducibility of patch testing: a cause for concern? A.-K. Björk, M. Bruze and C. Svedman Department of Occupational and Environmental Dermatology, University of Lund, Skåne University Hospital, Malmö, Sweden It is regularly stated that reactivity on various areas of the back differs, which might have a large impact on reproducibility at patch testing. The objective was to investigate reproducibility of patch testing on the upper back with regard to the left vs. the right side and the medial vs. the lateral part of the upper back. Reproducibility over time and with regard to reactivity pattern was also analysed. Thirty-one patients with contact allergy to gold (n = 19) or nickel (n = 12) were patch tested with serial dilutions. No significant differences in reactivity were found when comparing the left and right side of the upper part of the back and the medial and lateral part. In 19 of 19 gold allergic and 11 of 12 nickel allergic patients the allergy could be reproduced with regard to previous patch testing, but the degree of reactivity differed. This study provides clinical evidence that with regard to testing on the upper back, there seem to be no differences in whether the patch test is applied on the left vs. the right side of the back, or the medial vs. the lateral aspect of the back. P012 Facing the challenge: developing and validating approaches for the detection and quantification of skin-sensitizing hydroperoxides in consumer products A. Natsch, 1 M. Calandra, 2 H. Leijs, 3 J. Masson, 4 E. Corbi, 5 A. Duesterloh, 6 A.-T. Karlberg, 7 E. Giménez-Arnau, 8 J.-M. Aubry, 9 U. Nilsson, 10 M. Vey 11 and C. Gonzalez 11 1 Givaudan Schweiz AG, Duebendorf, Switzerland; 2 Firmenich US, Plainsboro NJ, U.S.A., 3 IFF, Tilburg, the Netherlands; 4 Robertet SA, Grasse, France; 5 Chanel SAS, Neuilly Sur Seine, France; 6 DSM Nutritional Products, Kaiseraugst, Switzerland; 7 University of Gothenburg, Gothenburg, Sweden; 8 University of Strasbourg, Strasbourg, France; 10 University of Stockholm, Stockholm, Sweden; 9 University of Lille, Lille, France; and 11 International Fragrance Association, Brussels, Belgium Recently, a high frequency of positive patch tests to oxidized linalool and limonene was reported from multiple clinical centres. However, there is a lack of data indicating potential sources of consumer exposure to sensitizing doses of terpene hydroperoxides, which are the key sensitizers in preparations of these oxidized materials. To understand the frequent patch tests and define potential actions needed, this gap needs to be closed. Within the International Dialogue for the Evaluation of Allergens (IDEA) project, three workshops were organized to look at the clinical data, the conditions leading to hydroperoxide formation and the question of significant exposure to hydroperoxides from fragranced products. IDEA formulated a programme that will drive analytical and mechanistic understanding of these potential reactions, which will eventually allow the development of a framework, broadly applicable to address the pre-/prohapten question in a meaningful approach. As one key action, a hydroperoxide analytical taskforce was established. This group (i) reviewed the analytical challenge, (ii) organized a reliable source for pure analytical standards 64 Contact Dermatitis, 75 (Suppl. 1),

6 and (iii) started two method-evaluation studies to compare different analytical methods to detect hydroperoxides in essential oils. Liquid chromatography mass spectrometry (MS) and gas chromatography MS methods with derivatization were tested. Based on the results of these initial steps, a new study was initiated to compare one of several promising methods for reproducibility between laboratories. At the same time, a broad range of different methods were compared on the same products. All these analyses were done on two real-life consumer products (eau de parfum and eau de toilette) spiked with defined, but blinded levels of hydroperoxides. The full results of this study will be presented to give a perspective on the status of this IDEA-guided project and discuss the remaining analytical challenge to measure true exposure of the public to sensitizing hydroperoxides. P013 Nonanimal approaches for sensitization potency: to what extent can local lymph node assay data provide a useful benchmark? D. Roberts Liverpool JM University, Liverpool, U.K. Prediction of sensitization potential and potency by in vitro, in chemico or in silico approaches, or by combinations of these, is the target of many active research programmes. Although the aim is to predict sensitization potential and potency in humans, local lymph node assay (LLNA) data provide the largest source of quantitative data on sensitization. The LLNA has been the preferred in vivo method for identification of skin-sensitizing chemicals; as such, it is potentially valuable as a benchmark against which the performance of nonanimal approaches can be judged. However, in common with all predictive test methods, the LLNA is subject to false-positive and false-negative results, with an overall level of accuracy said to be approximately 80 90%. It is also necessary to consider the extent to which, for true positives, LLNA potency correlates with human potency. In this presentation, LLNA potency (expressed as EC3) and human potency (expressed as no observed effect level value from human repeat insult patch test) are compared so as to express quantitatively the correlation between LLNA and human potency, and reasons for nonagreement between LLNA potency and human potency are analysed. This leads to a better definition of the applicability domain of the LLNA, within which LLNA data can be used confidently to predict human potency and as a benchmark with which to assess the performance of nonanimal approaches. P014 Abstract withdrawn P015 that particular individual. The amount of hapten deposited on the skin, the length of exposure and the ability of the hapten to actually penetrate and bind to proteins will be crucial in determining whether a clinically relevant allergic reaction will take place. The first two factors were investigated in this study. The aim was to study the release of gold from gold objects and the deposition of gold on the skin at exposure. Gold was found to be released from gold plates used in a provocation study in healthy individuals. Furthermore, gold was found on the skin following provocation. P016 Octylisothiazolinone is a relevant nonoccupational contact allergen in leather goods and may show cross-reactivity to methylisothiazolinone J. Leysen, 1 A. Goossens, 2 H. Meert, 3 S. Apers, 3 J. Lambert 1 and O. Aerts 1 1 University Hospital Antwerp, Dermatology, and University of Antwerp, Antwerp, Belgium, 2 University Hospitals KU Leuven, Dermatology, Leuven, Belgium and 3 University of Antwerp, Research Group NatuRA, Antwerp, Belgium Octylisothiazolinone (OIT; CAS ) is primarily an occupational contact allergen. It is used by the textile and leather industry as an antifungal agent. The objective was to report OIT as a relevant nonoccupational contact allergen in leather, and to show its potential cross-reactivity to methylisothiazolinone (MI). Two 34-year-old men were referred because of a severe, band-like eczema on the abdomen, and a dermatitis on the feet, respectively. Patch tests were performed with a standard series, cosmetic series, shoe series, textile series, selected rubber, glue and metal allergens, and dimethylfumarate 0.01% and 0.1% in petrolatum (pet.; all by Chemotechnique, Vellinge, Sweden). Moreover, ethanol ultrasonic bath extracts of leather pieces, of a leather belt and of leather shoes were also patch tested. All tests were placed on the upper back and removed after 48 h, with readings on days 2, 4 and 7. High-pressure liquid chromatography with ultraviolet detection (HPLC-UV) was used to determine isothiazolinone derivatives in the leather goods. In both patients, a primary sensitization to OIT was shown; however, in one of the patients, it was only detected with the higher patch test concentration of OIT 0.1% (1000 ppm) pet., while OIT 0.025% (250 ppm) pet. was negative. HPLC-UV confirmed the presence of rather high levels of OIT in the belt (171 ppm) and in the shoes (281 ppm). Nonrelevant sensitization to MI was noted in both patients; in one of them, it was only detected using the highest patch test concentration of MI, 0.2% (2000 ppm) aqua. Nonoccupational allergic contact dermatitis from OIT in leather goods may occur. Patch test concentrations of OIT > 250 ppm may be necessary to demonstrate OIT sensitization, and to show cross-reactivity to MI. Safer use limits for OIT in the textile and leather industry may be needed. The finding of gold on skin after gold exposure A.-K.Björk,C.SvedmanandM.Bruze Department of Occupational and Environmental Dermatology, University of Lund, Skåne University Hospital, Malmö, Sweden In order to elicit an allergic contact dermatitis, a sensitized person needs to be exposed to a dose exceeding the elicitation threshold of Contact Dermatitis, 75 (Suppl. 1),

7 P017 Photoaggravation and persistent photosensitivity in patients sensitized to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone in Belgium and France: a report of nine cases O. Aerts, 1 A. Goossens, 2 M.-C. Marguery, 3 M. Castelain, 4 L. Boursault, 5 F. Giordano-Labadie, 3 J. Lambert 1 and B. Milpied 5 1 University Hospital Antwerp, Dermatology, and University of Antwerp, Antwerp, Belgium, 2 University Hospitals KU Leuven, Dermatology, Leuven, Belgium, 3 Service Dermatologie, Hôpital Larrey, CHU Toulouse, Toulouse, France, 4 Dermatologie, Avenue de Montredon, Marseille, France and 5 Service Dermatologie, Hôpital St André, CHU Bordeaux, Bordeaux, France Photoaggravated contact dermatitis in patients allergic to methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) has been reported. The objective was to report on patients from Belgium and France suspected of having photoaggravated contact dermatitis and/or persistent photosensitivity due to MCI/MI and/or MI sensitization. This concerns nine patients, six from Belgium and three from France [five men, four women (median age 50 years)], all patch tested with a baseline series (containing MCI/MI and MI) and additional series, depending on their history. In five of nine patients photopatch tests with (cosmetics containing) MCI/MI and/or MI were performed. In one of the Belgian patients, photopatch tests were also performed with a dilution series of MI. In two French patients, phototests were also done. Six patients gave a history of potential aggravation of their dermatitis upon sun exposure, and in all the patients skin lesions were initially present in a photodistributed pattern (mainly the face and/or back of the hands), sometimes becoming generalized afterwards. Seven patients had patch test reactions to both MCI/MI and MI, while two were positive only to MI. In four of five patients investigated with photopatch tests, readings revealed stronger reactions upon irradiation of MCI/MI and/or MI, supporting a diagnosis of photoaggravated contact dermatitis. In one of these patients a dilution series of MI showed reactions down to lower concentrations on the irradiated side. In one patient, photopatch and patch tests to a sunscreen containing MI were of equal intensity. Sensitization to MCI/MI and/or MI occurred from cosmetics (four women, one man) or from work-related sources (biocides in two cases, paint in one case and an unknown source in another case all men). Subsequent airborne dermatitis occurred in all patients, which was attributed to water-based paints in seven of them. During follow-up, four patients, of whom three had a proven photoaggravated contact dermatitis, reported persistent photosensitivity, despite avoiding their allergens. In three of these patients even a relapse of their dermatitis occurred whenever they were exposed to sunlight, with two of these patients also having a lower minimal erythema dose upon phototesting with ultraviolet B. Although potentially difficult to differentiate from airborne allergic contact dermatitis, some patients sensitized to MCI/MI and/or MI may show photoaggravated dermatitis and/or persistent photosensitivity for which photopatch tests and phototests are useful diagnostic procedures. P018 Quantification of L-carvone in toothpastes available on the Swedish market L. Kroona, 1 J. Dahlin, 2 Ö. Sörensen, 2 M. Isaksson, 2 M. Bruze, 2 C. Ahlgren 3 and G. Warfvinge 1 1 Department of Oral Pathology and 3 Department of Prosthodontics, Malmö University, Malmö, Sweden and 2 Department of Occupational and Environmental Dermatology, Skåne University Hospital, Lund University, Malmö, Sweden A predominant part of the Swedish population uses toothpaste daily. Besides fluoride preventing caries, toothpastes usually have flavours added to make the user feel fresh and clean. Among potential allergens in toothpastes, flavours are the most common cause of oral or perioral lesions. Flavour concentrations vary between 0.3% and 2.0%, and usually several types of mint are used; however, the true composition of the added aroma is seldom known. L-Carvone is a mint-tasting flavour that can act as a potential allergen. Previous findings have shown that approximately 4% of a patch-tested selected population in southern Sweden had a positive reaction to L-carvone and half of them had oral inflammatory lesions, notably oral lichenoid lesions. Among patients with lichenoid lesions approximately 12% have a contact allergy to L-carvone and several other contact allergies are more common in this patient group. The concentration of L-carvone in toothpastes available for sale on the Swedish market was investigated. Sixty-six different toothpastes were selected from local stores and pharmacies. L-Carvone content was extracted from toothpastes using n-heptane. The sample extracts were separated on a silica column using straight-phase high-performance liquid chromatography and a diode-array detector. Three samples of each toothpaste were analysed, and the mean concentration and relative SD were calculated. Detectable levels of L-carvone ( %) were found in 63 of the toothpastes. L-Carvone was found in half of the toothpastes (n = 32) at a concentration of 0.01%. A higher concentration ( 0.1%) was found in 18% (n = 12). Of the top six toothpastes with highest L-carvone content ( %), one was intended for use by children. Two of the toothpastes were stated as having fruit flavour, but there were still detectable levels of L-carvone (0.0003% and %, respectively). L-Carvone was below detectable levels in three of the toothpastes, where one was stated as being without flavour. L-Carvone is present in virtually all toothpastes on the Swedish market. It is therefore likely that L-carvone in toothpastes is important for the induction of sensitization to L-carvone, as contact allergy to L-carvone is over-represented in patch-tested individuals with oral lichenoid reactions. However, are the concentrations demonstrated relevant for causing reactions or aggravating already existing lesions? 66 Contact Dermatitis, 75 (Suppl. 1),

8 P019 Some preparations of hydroperoxides of linalool give lower response rates because hapten concentrations are less than indicated M. Abbas, 1 A. Ibrahim, 2 U. Nilsson, 2 W. Moffat, 3 J. DeKoven, 4 K. Suzuki 1 and J. Elliott 1 1 Division of Dermatology, Departments of Medicine and Medical Microbiology and Immunology, and 3 Department of Chemistry, University of Alberta, Edmonton, AB, Canada; 2 Department of Analytical Chemistry and Environmental Science (ACES), Stockholm University, Stockholm, Sweden and 4 Division of Dermatology, Sunnybrook Hospital, University of Toronto, Toronto, ON, Canada Linalool is a very common fragrance ingredient in consumer products. In its pure form, linalool is not a sensitizer, but exposure to air at room temperature leads to the formation of linalool hydroperoxides (Lin-OOH), which are potent sensitizers. Recent international and European reports indicate that positive patch test responses to Lin-OOH occur frequently ( %), but rates in Canada are not known. The objective was to compare rates of positivity to Lin-OOHs between two different patch test clinics in Canada, one in Edmonton, and the other in Toronto, and to analyse chemically Lin-OOH patch test preparations used in Edmonton and Toronto. Statistical analysis was used to determine overall response rates (ORR) and Clopper Pearson 95% confidence intervals (CI). Purity/concentration of patch test products was evaluated using gas chromatography (GC)/mass spectrometry (MS) and liquid chromatography (LC)/MS analysis. Edmonton began testing to Lin-OOH in August 2014, with 484 patients tested up to October A total of 47 patients showed a positive response at 96 h (1+, n = 45; 2+, n = 2), with an ORR of 9.7% (Clopper Pearson 95% CI ). Sunnybrook began testing Lin-OOH in March 2015, with 196 patients tested to October 2015; four patients were positive (3+, n = 1; 1+, n = 3), giving an ORR of 2.0% (Clopper Pearson 95% CI %). Surprisingly, a statistically significant difference between the two sites was demonstrated (χ 2 = 11.8; P < 0.01). Further inquiry revealed that Sunnybrook had used exclusively Allergeaze/SmartPractice (Calgary, AB, Canada) hapten preparation, whereas Edmonton had used exclusively Chemotechnique (Vellinge, Sweden). GC/MS analysis showed that the Chemotechnique syringe contained significantly higher relative concentrations of linalool oxidation products compared with the Allergeaze/SmartPractice syringe, although exact concentrations could not be determined by this method. LC/MS analysis showed that the Chemotechnique syringe contained about a sixfold higher concentration of Lin-OOH compared with the Allergeaze/SmartPractice syringe ( % vs. 0.1%), despite the fact that both syringes were labelled as containing 1% Lin-OOH. The Toronto clinic observed a lower response rate to Lin-OOH compared with Edmonton (2.0% vs. 9.7%), primarily because the concentration of Lin-OOH in the Allergeaze/SmartPractice syringes used in Toronto was about sixfold lower than the Chemotechnique syringes used in Edmonton. Measuring the concentration of Lin-OOH in patch test materials is technically demanding. Although GC/MS analysis provides a rapid and economical screening tool, LC/MS analysis is needed for definitive analysis. (Note: Allergeaze/SmartPractice recently removed Lin-OOH from its catalogue.) Funding sources: Canadian Dermatology Foundation and Swedish Asthma and Allergy Association funded this study. P020 Airborne bullous allergic contact dermatitis from methyl isothiazolinone contained in a glass shower screen cleaning spray M.A. Pastor-Nieto, 1,2 M.E. Gática-Ortega, 3 P. González-Muñoz, 1 C. Perna-Monroy, 4 R. Gil-Redondo, 1 R. Pérez-Mesonero, 1 V. Melgar-Molero, 1 F. Alcántara-Nicolás, 1 L. Hernández-Caballero 1 and A. Vieira-Pereira 1 1 Dermatology Department, University Hospital of Guadalajara, Guadalajara, Spain, 2 Alcalá de Henares University, Alcalá de Henares, Madrid, Spain, 3 Virgen de La Salud Hospital, Toledo, Spain and 4 Pathology Department, Ramón y Cajal Hospital, Madrid, Spain A 79-year-old woman presented to our department with a reaction, consisting of tense blisters measuring several cm in diameter, of several months duration that involved the lateral aspects of the lower third of her legs and ankles. Isolated smaller but similar lesions on the lateral sides of her arms and a subtle erythema involving her cheeks and nasolabial folds were also observed. In order to rule out an immune bullous disease, two biopsies were performed, which both showed intraepidermal blisters with spongiotic changes at the peripheral epidermis, and a sparse superficial inflammatory infiltrate containing eosinophils within the dermis. Direct immunofluorescence testing was negative. Patch tests with the baseline standard Spanish Contact Dermatitis Research Group (GEIDAC) cosmetic and corticosteroid series, and a photopatch test with the photoallergen series were performed. Positive results were achieved with methylisothiazolinone and methylisothiazolinone (3+ on day 4). Patch tests with benzyl isothiazolinone and octyl isothiazolinone were negative. The patient then stated that she had been using a glass shower screen cleaning spray. She usually sprayed it on the glass immediately after showering, while she was still naked inside her walk-in shower. The product contained methylisothiazolinone and benzylisothiazolinone. She had not used any personal care products containing isothiazolinones. The lesions completely cleared after she stopped using the product and has remained disease free for several months. Bullous allergic contact dermatitis has been described in relation to several allergens, such as acrylates, several types of plants, pure henna, paraphenylenediamine and lidocaine, among others. To the best of our knowledge, there are no previous reports of bullous contact dermatitis from methylisothiazolinone. However, there have been several publications regarding cases of allergic contact dermatitis caused by airborne isothiazolinones. Most of the cases are due to exposure to water-based paints, for example professionals applying the product and individuals being exposed to recently painted buildings. In these contexts, isothiazolinones may cause severe cutaneous and respiratory symptoms, primary sensitization and even systemic dermatitis from inhalation. Domestic cleaning products such as ironing water and toilet cleaners have been described as sources of methylisothiazolinone inducing allergic contact dermatitis. This would be the first time that a glass shower screen cleaning spray containing methylisothiazolinone has been identified as the cause of airborne contact dermatitis. Contact Dermatitis, 75 (Suppl. 1),