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Differences in consumer product availability, distribution, and use may lead to national differences in contact sensitization frequencies. Objective The aim of the study was to describe the differences in contact allergy between the United States (US) and Canada. Methods This is a retrospective cross-sectional analysis of the North American Contact Dermatitis Group data from 2005 to 2016. Frequencies of demographics, clinical characteristics, positive reactions, trends, and occupations were calculated. Results A total of 28,640 patients underwent patch testing. At least 1 positive patch test was observed in 18,599 patients (US, 11,641 [66.5%]; Canada, 6958 [62.5%]). When comparing the 2 groups, US positive reactions were more likely to occur in male patients (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.31-1.49), older than 40 years (OR = 1.30, 95% CI = 1.22-1.38), Black (OR = 2.67, 95% CI = 2.24-3.19) or Hispanic race (OR = 3.53, 95% CI = 2.61-4.78), and/or patients with scattered generalized dermatitis (OR = 1.96, 95% CI = 1.80-2.13). They were less likely to occur in patients with eczema (OR = 0.61, 95% CI = 0.57-0.65) and Asian race (OR = 0.50, 95% CI = 0.44-0.56). Nickel (US, 16.0%; Canada, 22.4%) and methylisothiazolinone (US, 13.4%; Canada, 11.0%) were the top allergens. The third most frequent was neomycin (US, 11.7%) and fragrance mix I (Canada, 10.2%). Conclusions National differences in allergen prevalence and trends exist in North America.

BACKGROUND Vitamin E (tocopherol) a naturally occurring mixture of antioxidants commonly used in topical skin care products, may cause allergic contact dermatitis. OBJECTIVE The aim of this study was to characterize positive patch test reactions to tocopherol and tocopherol acetate. METHODS This is a retrospective analysis of North American Contact Dermatitis Group patch test data to tocopherols (dl-α-tocopherol 100% and/or dl-α-tocopherol acetate 100%) from 2001 to 2016. RESULTS Of the 38,699 patients patch tested to tocopherol and/or tocopherol acetate, 349 (0.9%) had positive reactions; of these, 87.6% were currently relevant. Most (51.4%) were weak (+) and/or not related to occupation (99.1%). Compared with tocopherol-negative patients, tocopherol-positive individuals were more likely to be female (72.5% vs 67.2%, P = 0.0355), have a final primary diagnosis of allergic contact dermatitis (74.2% vs 52.6%, P < 0.0001), and have dermatitis in a scattered generalized distribution (23.8% vs 18.2%, P = 0.0072); they were also less likely to have hand involvement (16.6% vs 22.3%, P = 0.0064). The most common source of tocopherol was personal care products, especially moisturizers. CONCLUSIONS Positive patch test reactions to tocopherols were relatively rare given their widespread use. When positive, current clinical relevance was high. Tocopherol-positive patients were more likely to be female and presented with dermatitis on the face or in a scattered generalized pattern.

BACKGROUND/OBJECTIVE This study characterizes concomitant reactions to carba mix (CM) and thiuram mix (TM) in a large North American population. Because thiurams and dithiocarbamates have structural similarity, concomitant reactions are expected. METHODS The 1994-2016 North American Contact Dermatitis Group data were analyzed. Patients with a final reaction interpreted as "allergic" to either CM or TM were included. RESULTS A total of 49,758 patients were tested to both CM and TM. A total of 3437 (6.9%) had positive reactions to CM and/or TM including the following groups: CM+ only (n = 1403, 40.8%), TM+ only (n = 1068, 31.0%), or both (n = 966, 28.1%). A total of 47.5% of TM+ patients were positive to CM and 40.8% of CM+ patients were positive to TM. Male sex, occupationally related dermatitis, and hand involvement were significantly more common in individuals positive to CM and/or TM as compared with those who were negative (P < 0.0001). More than 80% of CM+/TM+ reactions were currently relevant. Gloves were the most common source of CM and TM; clothing and footwear were also frequent. CONCLUSIONS Carba mix and TM remain important, clinically relevant allergens. Although significant concomitant reaction frequency was demonstrated, more than half of the patients reacting to either CM or TM would have been missed if both had not been tested, underscoring the importance of testing to both.

IMPORTANCE When fragrance- and botanical-related (F/BR) allergy is identified, concomitant reaction (CR) frequencies can help direct avoidance recommendations. OBJECTIVE This study aimed to determine the CR rates for F/BR allergens. DESIGN A retrospective cross-sectional analysis of the North American Contact Dermatitis Group data 2007-2016 was conducted. Frequencies of demographics, positive reactions, strength of reactions, trends, and CR rates were calculated. RESULTS A total of 5504 (22.7%) of 24,246 patients had F/BR allergic reactions. The F/BR-sensitive patients were more likely to be female, older than age 40 years, and White and have face, leg, or anal/genital dermatitis. Top allergens included fragrance mix I (FMI, 10.6%), Myroxylon pereirae (balsam of Peru [BOP], 8%), and fragrance mix II (FMII, 4.9%). There were increasing trends for FMI, FMII, cinnamic aldehyde, and Compositae mix and decreasing trends for BOP and propolis. When patients were positive to any F/BR allergen, they were likely to be positive to FMI, FMII, and BOP. Concomitant reactions were bidirectional between multiple fragrance allergens and propolis, colophony, and Compositae mix. CONCLUSIONS Concomitant reactions were identified between fragrances, between fragrances and BR allergens, and between BR allergens and fragrances. If CRs of greater than 10% suggest cross-reactivity, then all patients with fragrance sensitivity should avoid BR allergens and vice versa.

BACKGROUND Hair care products (HCPs) may cause both allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD). OBJECTIVES The aims of the study were to determine the prevalence of HCP-associated ICD/ACD and to characterize relevant allergens. METHODS This study is a retrospective analysis of North American Contact Dermatitis Group (NACDG) patch test data, 2001-2016. RESULTS Of 38,775 patients tested, 3481 (9.0%) had positive patch test reactions associated with HCPs. The HCP-positive patients were significantly more likely to be female (79.9% vs 66.0%) and/or have primary sites of dermatitis on the face (32.0% vs 27.8%) or scalp (15.4% vs 2.2%) compared with the HCP-negative patients (P < 0.0001). Of 4908 HCP-associated positive patch test reactions, 86.9% (n = 4263) were due to allergens on the NACDG screening series; p-phenylenediamine (35.8%), methylisothiazolinone (9.7%), methylchloroisothiazolinone/methylisothiazolinone (8.7%), and cocamidopropyl betaine (5.9%) were the most frequent. Most reactions (87.7%, 3736/4263) were currently clinically relevant. The most common job associated with 366 occupationally related NACDG HCP-associated allergens was hairdresser/cosmetologist (71.9%). Two hundred eighty-two patients (0.7%) had ICD associated with HCPs. Shampoo/conditioners were the most frequent source of NACDG HCP-associated reactions (47.3%) and HCP-associated ICD (45.0%). CONCLUSIONS Of the HCP-positive patients, 18.5% had HCP reactions to allergens not on the NACDG screening series, underscoring the importance of patch testing to expanded series in patients suspected of HCP allergy.

BACKGROUND The epidemiology of nickel allergy in occupational settings is not well understood. OBJECTIVE The aim of the study was to characterize occupationally related nickel allergy (ORNA). METHODS This is a retrospective cross-sectional analysis of 44,378 patients patch tested by the North American Contact Dermatitis Group from 1998 to 2016. Characteristics of individuals with ORNA were compared with those with non-ORNA (NORNA). RESULTS A total of 7928 (18.2%) individuals were positive to nickel sulfate 2.5%. Two hundred sixty-eight (3.4%) had ORNA. As compared with NORNA, ORNA was statistically associated with the male sex (41.0% vs 12.9%, P < 0.001), a diagnosis of irritant contact dermatitis (22.4% vs 12.0%, P < 0.001), and no history of eczema (81.7% vs 75.7%, P = 0.0217). The most common sites of ORNA dermatitis were hand (39.9%) and arm (18.1%), which were significantly more common than in NORNA (P < 0.0001). Sixteen industry categories and 22 occupation categories were identified for ORNA; the most common industries were durable goods manufacturing (24.6%) and personal services (15.7%), and the most frequent occupations were hairdressers/cosmetologists/barbers (14.3%), machine operators (9.3%), and health care workers (7.1%). Overall 30% of ORNA occupations were in metalworking. Of 215 ORNA sources identified, instruments/phones/other equipment (16.3%), vehicles/machinery (15.8%), and tools (15.3%) were the most common. CONCLUSIONS Occupational nickel allergy is distinct from nonoccupational nickel allergy.

Parabens have been widely used as preservatives in the cosmetics, food, and pharmaceutical industries for more than 70 years. Monitoring for paraben allergy closely followed with studies reporting paraben testing in standard screening fashion as early as 1940. The frequency of sensitivity to this widely used biocide has remained low and remarkably stable for many decades despite extensive use and progressive expansion of utilization worldwide. The authors select paraben mix as the (non)allergen of the year. Paraben reactions are quite uncommon and generally relevant. Parabens remain one of the least allergenic preservatives available. The unsubstantiated public perception of paraben safety has led to its replacement in many products with preservatives having far greater allergenic potential. This report reviews the well-established safety of parabens from an allergologic standpoint.

BACKGROUND Body piercing provides a unique route of metal exposure. OBJECTIVE The aim of this study was to update previous analyses using the North American Contact Dermatitis Group data comparing pierced and unpierced individuals. METHODS This was a retrospective cross-sectional analysis of 17,912 patients patch tested by the North American Contact Dermatitis Group from 2007 to 2014 for demographics, positive reactions to metals (nickel, cobalt, chromium), and detailed analysis of nickel reactions by age, sex, and source of exposure. RESULTS Piercing was significantly associated with female sex, being older than 18 years, and atopy (P < 0.003). Nickel sensitivity was associated with 1 or more piercing for men and women combined (P < 0.0001; relative risk [RR], 2.54; 95% confidence interval [CI], 2.35-2.75), although this association was stronger for men (RR, 2.21; 95% CI, 1.77-2.76) than women (RR, 1.47; 95% CI, 1.31-1.65). The frequency of positivity to nickel increased with number of piercings (14.3% for 1 piercing to 34.0% with ≥5 piercings). Piercing was not significantly associated with cobalt sensitivity alone (P = 0.8992) and was negatively associated with chromium sensitivity (P < 0.0001). Jewelry was the most common source of allergic reactions to nickel irrespective of sex or pierced status. CONCLUSIONS Nickel sensitivity was significantly associated with piercing in both men and women. Jewelry was the most common source.

Background Synthetic fragrances and natural essential oils (EOs) are used in perfumery and found in various cosmetics. Essential oils are also increasingly used to promote wellness. In previous studies, the sensitization potential of some EOs has been identified; however, the current prevalence of sensitivity is largely unknown. Objectives The aim of this study was to determine frequency of positive patch-test reactions to EOs tested in the baseline series, along with 3 fragrance markers (FMs) (fragrance mix I, fragrance mix II, and Myroxylon pereirae), in consecutive patients in the US/Canadian North American Contact Dermatitis Group (NACDG) (2009-2014) and the central European, trinational Information Network of Departments of Dermatology (IVDK) (2010-2014). Methods This study used a retrospective analysis of patch-test results and relevant demographic/clinical data collected electronically by the networks, obtained with Santalum album 10% petrolatum (pet) (IVDK only); Cananga odorata 2% (NACDG) and 10% (IVDK) pet; Jasminum species 2% (NACDG) and 5% (IVDK) pet; Mentha piperita 2% pet; Melaleuca alternifolia, oxidized (tea tree oil), 5% pet; and Lavandula angustifolia 2% pet (latter 3 NACDG only). Results Overall, 62,354 patients were tested to 3 FMs and EOs (NACDG, 13,398; IVDK, 48,956); 11,568 (18.6%) reacted to at least 1 FM or EO, whereas 857 (1.4%) reacted to 1 or more EOs but none of the 3 FMs. For both the NACDG and IVDK populations, individuals who were positive to 1 or more of the 9 study allergens were significantly less likely to be male, have occupational skin disease, or have hand involvement and significantly more likely to have leg dermatitis and be 40 years and older (P's ≤ 0.005). Prevalence rates for EOs were as follows: S. album, 1.4% IVDK; C. odorata, 1.1% NACDG and 2.4% IVDK; Jasminum species, 0.7% NACDG and 1.4% IVDK; M. piperita, 0.9% NACDG; L. angustifolia, 0.3% NACDG; and M. alternifolia, 0.3% NACDG. Of the 140 NACDG patients who reacted to 1 or more of the 5 NACDG EOs but none of the FMs, M. alternifolia yielded most positive reactions (45%); half of these reactions were strong (++ or +++, 50.8%) and of definite/probable clinical relevance (52.4%). Of the 717 IVDK patients who reacted to 1 or more of the 3 IVDK EOs but none of the 3 FMs, 38% were positive to C. odorata, 38% to S. album and 36% to Jasminum species.' Conclusions Testing to EOs may be important for detecting sensitivity not detected by FMs alone. In North America, M. alternifolia is an important and clinically relevant sensitizer often not detected by FM. In Europe, as well as in North America, clinical relevance is often difficult to evaluate because (1) labeling of EOs when used as fragrance is not mandatory, and (2) these mixtures may indicate sensitization to 1 or more of their individual constituents from other sources, including synthetic fragrances.

BACKGROUND Little is known about the epidemiology of contact dermatitis in production workers (PWs). OBJECTIVE The aims of this study were to estimate the prevalence of contact dermatitis and characterize clinically relevant and occupationally related allergens among North American PWs undergoing patch testing. METHODS This was a retrospective cross-sectional analysis of North American Contact Dermatitis Group data from 1998 to 2014. RESULTS Of 39,332 patch-tested patients, 2732 (7.0%) were PWs. Among PWs, most were men (62.4%) and white (83.9%). A history of childhood eczema was uncommon (11.3%). Prevalent occupations included machine operators (27.3%); fabricators, assemblers, and hand-working occupations (16.8%); and precision metalworking occupations (16.1%). The most frequent sites of dermatitis were the hands (53.8%) and arms (29.4%), which were significantly more commonly affected compared with non-PWs (P < 0.0001). Occupationally related skin disease, allergic contact dermatitis, and irritant contact dermatitis were also significantly more common in PWs (49.9% vs 10.6%, 58.9% vs 53.7%, and 32.7% vs 25.7%, respectively; all Ps < 0.0001). Epoxy (15.3%), thiuram mix (8.3%), carba mix (8.1%), formaldehyde (6.3%), and cobalt (5.9%) were the most frequent occupationally related allergens. The top allergen sources included adhesives/glues (16.0%), metalworking fluids/cutting oils (6.8%), and coatings (6.3%). CONCLUSIONS Production workers had a high rate of occupationally related skin disease, as well as irritant and allergic contact dermatitis. Involvement of exposed body areas was common. Frequently identified allergens included adhesives/glues, rubber accelerators, metals, and preservatives.

INTRODUCTION Corticosteroids may cause delayed hypersensitivity. On the basis of structure, the following 4 groups of corticosteroids are recognized: A, B, C, and D (subdivided into D1 and D2). More recently, a newer classification system subdivides corticosteroids into groups 1, 2, and 3. Cross-reactions are unpredictable. The objective of this study was to describe positive patch test and co-reaction patterns to corticosteroids. METHODS AND RESULTS A retrospective analysis of 17,978 patients patch tested by the North American Contact Dermatitis Group between 2007 and 2014 was performed. Corticosteroids tested during this period included the following: tixocortol-21-pivalate 1.0% petroleum (pet), budesonide 0.1% pet, triamcinolone acetonide 1.0% pet, desoximetasone 1.0% pet, clobetasol-17-propionate 1.0% pet, and hydrocortisone-17-butyrate (HC-17-B) 1.0% (pet and alcohol). Overall, 4.12% (n = 741) of patients had 1 or more positive reactions to corticosteroids. Tixocortol-21-pivalate positivity was the most common (2.26%), followed by budesonide (0.87%), HC-17-B (0.43%), clobetasol-17-proprionate (0.32%), and desoximetasone (0.16%). Reaction strength was strong (++ or +++) in almost twice as many tixocortol and budesonide reactions (>64%) as compared with the other 3 corticosteroids (

BACKGROUND Although there are several case reports of wet wipe-associated contact dermatitis, the prevalence of wipes as a source of allergic contact dermatitis in larger populations and the responsible allergens are largely unknown. OBJECTIVE The aim of the study was to determine the prevalence of wet wipes as a source of contact allergy and the most commonly associated allergens in a North American tertiary referral patch test population. METHODS Data collected from 2011 to 2014 by the North American Contact Dermatitis Group was used to conduct a retrospective cross-sectional analysis of patient demographics and patch test results associated with the triple-digit source code for "wet wipe." RESULTS Of the 9037 patients patch tested during the study period, 79 (0.9%) had a positive patch test reaction to an allergen identified with a wet wipe source. The most commonly associated allergens were preservatives, including the following: methylisothiazolinone (MI) (59.0%), methylchloroisothiazolinone (MCI)/MI (35.6%), bronopol (2-bromo-2-nitropropane-1,3-diol) (27.4%), and iodopropynyl butylcarbamate (12.3%). Fragrance (combined) represented 12.3%. Anal/genital dermatitis was 15 times more likely (P < 0.0001) in those with wet wipe allergy. More than 92% of patients with wipe-associated contact allergy had their contact allergens detected by the North American Contact Dermatitis Group screening series. CONCLUSIONS Wet wipes are an important source of contact allergy. Preservatives are the main allergens, especially isothiazolinones.

Cobalt has been a recognized allergen capable of causing contact dermatitis for decades. Why, therefore, has it been named 2016 "Allergen of the Year"? Simply put, new information has come to light in the last few years regarding potential sources of exposure to this metallic substance. In addition to reviewing some background on our previous understanding of cobalt exposures, this article will highlight the recently recognized need to consider leather as a major site of cobalt and the visual cues suggesting the presence of cobalt in jewelry. In addition, a chemical spot test for cobalt now allows us to better identify its presence in suspect materials.

Background Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). Objective This study documents the North American Contact Dermatitis Group (NACDG) patch-testing results from January 1, 2011, to December 31, 2012. Methods At 12 centers in North America, patients were tested in a standardized manner with a series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends analyzed using χ statistics. Results Four thousand two hundred thirty-eight patients were tested; of these, 2705 patients (63.8%) had at least 1 positive reaction, and 2029 (48.0%) were ultimately determined to have a primary diagnosis of ACD. Four hundred eight patients (9.6%) had occupationally related skin disease. There were 7532 positive allergic reactions. As compared with previous reporting periods (2009-2010 and 2000-2010), positive reaction rates statistically increased for 6 allergens: methylchloroisothiazolinone/methylisothiazolinone (5.0%; risk ratios [RRs]: 2.01 [1.60-2.52], 1.87 [1.61-2.18]), lanolin alcohol (4.6%; RRs 1.83 [1.45-2.30], 2.10 [1.79-2.47]), cinnamic aldehyde (3.9%; 1.69 [1.32-2.15], 1.53 [1.28-1.82]), glutaral (1.5%; 1.67 [1.13-2.48], 1.31 [1.00-1.71]), paraben mix (1.4%; 1.77 [1.16-2.69], 1.44 [1.09-1.92]), and fragrance mix I (12.1%; RRs 1.42 [1.25-1.61], 1.24 [1.14-1.36]). Compared with the previous decade, positivity rates for all formaldehyde-releasing preservatives significantly decreased (formaldehyde 6.6%; RR, 0.82 [0.73, 0.93]; quaternium-15 6.4% RR 0.75 [0.66, 0.85]; diazolidinyl urea 2.1%; RR, 0.67 [0.54, 0.84]; imidazolidinyl urea 1.6%, 0.60 [0.47, 0.77]; bronopol 1.6%; RR, 0.60 [0.46, 0.77]; DMDM hydantoin 1.6%; RR, 0.59 [0.54, 0.84]). Approximately a quarter of patients had at least 1 relevant allergic reaction to a non-NACDG allergen. In addition, approximately one-fourth to one-third of reactions detected by NACDG allergens would have been hypothetically missed by T.R.U.E. TEST (SmartPractice Denmark, Hillerod, Denmark). Conclusions These data document the beginning of the epidemic of sensitivity to methylisothiazolinones in North America, which has been well documented in Europe. Patch testing with allergens beyond a standard screening tray is necessary for complete evaluation of occupational and nonoccupational ACD.

Background Allergic contact dermatitis is common in children. Epicutaneous patch testing is an important tool for identifying responsible allergens. Objective The objective of this study was to provide the patch test results from children (aged ≤18 years) examined by the North American Contact Dermatitis Group from 2005 to 2012. Methods This is a retrospective analysis of children patch-tested with the North American Contact Dermatitis Group 65- or 70-allergen series. Frequencies and counts were compared with previously published data (2001-2004) using χ statistics. Conclusions A total of 883 children were tested during the study period. A percentage of 62.3% had ≥1 positive patch test and 56.7% had ≥1 relevant positive patch test. Frequencies of positive patch test and relevant positive patch test reaction were highest with nickel sulfate (28.1/25.6), cobalt chloride (12.3/9.1), neomycin sulfate (7.1/6.6), balsam of Peru (5.7/5.5), and lanolin alcohol 50% petrolatum vehicle (5.5/5.1). The ≥1 positive patch test and ≥1 relevant positive patch test in the children did not differ significantly from adults (≥19 years) or from previously tested children (2001-2004). The percentage of clinically relevant positive patch tests for 27 allergens differed significantly between the children and adults. A total of 23.6% of children had a relevant positive reaction to at least 1 supplemental allergen. Differences in positive patch test and relevant positive patch test frequencies between children and adults as well as test periods confirm the importance of reporting periodic updates of patch testing in children to enhance clinicians' vigilance to clinically important allergens.

OBJECTIVE This study aimed to examine the association between piercing and patch test sensitivity to metals (nickel, cobalt, and chromium) in North America. METHODS A retrospective analysis of 9334 patients tested by the North American Contact Dermatitis Group from 2007 to 2010 was conducted. RESULTS Nickel sensitivity was statistically associated with at least 1 piercing (risk ratio [RR], 2.52; 95% confidence interval [CI], 2.26-2.81; P < 0.0001) and nickel sensitivity rates increased with the number of piercings (16% for 1 piercing to 32% for ≥ 5 piercings). Prevalence of nickel sensitivity was higher in females (23.2%) than in males (7.1%), but the association with piercing was stronger in males (RR, 2.38; 95% CI, 1.72-3.30; P < 0.0001) than in females (RR, 1.30; CI, 1.13-1.49; P = 0.0002). Crude analysis indicated that cobalt sensitivity was statistically associated with piercing (RR, 1.63; 95% CI, 1.40-1.91; P < 0.0001); however, stratified analysis showed that this relationship was confounded by nickel. After adjusting for nickel sensitivity, the adjusted risk ratio for piercing and cobalt was 0.78 (not significant). Chromium sensitivity was negatively associated with piercing (RR, 0.60; 95% CI, 0.48-0.75; P < 0.0001). CONCLUSIONS Piercing was statistically associated with sensitivity to nickel. This relationship was dose dependent and stronger in males. Cobalt sensitivity was not associated with piercing when adjusted for nickel. Chromium sensitivity was negatively associated with piercing.

BACKGROUND Repeated and prolonged use of surfactants can cause irritant as well as allergic contact dermatitis. OBJECTIVE This study reports the frequency of positive patch test results to surfactants tested on the North American Contact Dermatitis Group screening series including cocamidopropyl betaine (CAPB), amidoamine (AA), dimethylaminopropylamine (DMAPA), oleamidopropyl dimethylamine (OPD), and cocamide diethanolamide (CDEA), and correlations of positive reactions between CAPB and the other surfactants. METHODS This was a retrospective analysis of 10 877 patients patch tested between 2009 and 2014 to the surfactants CAPB, AA, DMAPA, OPD, and CDEA. Frequencies of positive reactions to these surfactants were calculated, and trends of reactivity between the surfactants analyzed. CONCLUSIONS The OPD had the highest rate of positive patch reactions (2.3%) followed by DMAPA (1.7%), and CAPB (1.4%). The AA and CDEA had the lowest rate of positive reactions (0.8%). There was a high degree of overlap in positive patch tests between the surfactants. The CDEA was the least likely to coreact with another surfactant.

Background Mercaptobenzothiazole (MBT) and mercapto compounds are primarily used in rubber products. Objective This study aimed to examine concomitant-positive rates of MBT (1% pet) and the 4-part mercapto mix (MM) (1% pet). Design This is a retrospective cross-sectional data from the North American Contact Dermatitis Group. Results A total of 30,880 patients were patch tested to MM and MBT. There were 333 positive reactions to MM and 427 positive reactions to MBT. Ninety-eight patients were positive to MM alone, 192 to MBT alone, and 235 reacted to both. Forty-five percent (192/427) of MBT reactions would have been missed by only testing to MM, and 29% (98/333) of MM reactions would have been missed by testing to MBT alone. Most of these "missed" reactions, however, were doubtful (+/-) or mild (+) (MBT, 65%; MM, 78%), whereas most reactions in patients who reacted to both were moderate (++) and/or strong (+++) (52.3%). Gloves were the most common source. Conclusions Mercaptobenzothiazole is the preferential screening allergen for mercapto compounds because of the following: (1) greater proportion of missed reactions with MM; (2) greater proportion of doubtful/mild reactions in the missed group for MM; and (3) in the group positive to both, the low rate (2%) of moderate/strong reactions to MM and doubtful/mild reactions to MBT as compared with the converse (21%). Mercapto mix may be useful in an auxiliary rubber series.

Background Carba mix (CM) contains 3 chemicals used as accelerators in manufacturing of rubber products and agricultural chemicals. Iodopropynyl butylcarbamate (IPBC) is a preservative used in industrial and personal care products. Potential cross-reactivity between these allergens is unclear. Objective This study aimed to determine concomitant reaction rates between CM (3% petrolatum [pet]) and IPBC (0.1% pet and/or 0.5% pet). Design A retrospective cross-sectional analysis of data from the North American Contact Dermatitis Group from 1998 to 2008 was conducted. Frequencies of positive reactions, strength of reactions, and concomitant reaction rates were calculated. Results A total of 25,435 patients were tested. There were 1131 allergic reactions to CM and 346 positive reactions to IPBC (either 0.1% pet and/or 0.5% pet). Fifty-two patients reacted to both allergens. Most reactions (>69%) were doubtful/weakly positive, and of those who reacted to both, most (58%) had doubtful and/or weakly positive reactions. There was a statistically significant association of concomitant reactions between CM and IPBC; formaldehyde positivity was used as control and showed statistically significant concomitant reactions. Conclusions Overall, concomitant reactions to CM and IPBC were low, and rates varied by strength of reaction. True cross-reactivity is unlikely; statistical association is likely due to frequent low-grade reactions to irritant patch test preparations.

Background iodopropynyl butylcarbamate (IPBC), a commonly used preservative, is found in industrial and personal care products. Objective to evaluate prevalence, clinical relevance, occupational relationship, and sources of positive reactions to IPBC in patients in North America. Methods the North American Contact Dermatitis Group (NACDG) tested IPBC 0.1% and/or 0.5% in petrolatum (pet) between 1998 and 2008. Two patient groups of interest were defined, based on patch-test reactions to IPBC: weak (+) reactors and strong (++ or +++) reactors. Patient characteristics, site(s) of dermatitis, sources of positive reactions, clinical relevance, and occupational relevance to IPBC were tabulated. Results of the 25,321 patients tested, there were 226 (0.9%) weak reactors and 67 (0.3%) strong reactors. For IPBC-positive patients, the most frequent sites of dermatitis were scattered generalized distribution, hands, and arms. The majority (> 50%) of currently relevant reactions were to personal care products, and most reactions (> 90%) were not related to occupation. Only four of the strong reactors had definite clinical relevance (positive use-test reaction or positive patch-test reaction to a product containing IPBC). The frequency of positive reactions increased (0.2% vs 1.5%) when the higher concentration of IPBC was utilized, but most (> 64%) were weak reactions, of which some were likely irritant. Conclusions allergy to IPBC is relatively uncommon. When clinically relevant, personal care products were the most likely allergen source. Because IPBC is a marginal irritant, caution should be utilized when testing with higher concentrations of IPBC (≥ 0.5% pet) and when interpreting weak (+) reactions. Verification of clinical relevance by use test or repeat patch testing or both is also important.

BACKGROUND The methylphenidate transdermal system (MTS) (Daytrana [Shire Pharmaceuticals Ireland Ltd., Wayne, PA]) has been shown to be well tolerated and effective; however, skin reactions, typically redness and itching, have also been noted with MTS use. OBJECTIVE The purpose of this study was to determine the irritancy threshold of methylphenidate (MPH), the active ingredient in the MTS, in healthy adults for use in subsequent patch testing. METHODS This was an open-label single-site pilot study. Eligible subjects had MPH (six different concentrations in two vehicles) patch tests applied to the paraspinous region of the upper back. Subjects returned after 48 hours and 96 hours for investigator assessments of each reaction. RESULTS All enrolled subjects (n = 20) completed the study. There were no definite positive reactions in any subject at any test concentration. Overall, doubtful (macular erythema) reactions were noted on 12 sites at the 48-hour reading and on 6 sites at the 96-hour reading. With both aqueous and petrolatum vehicles, more doubtful reactions were noted at the lower MPH test concentrations. CONCLUSION When performing patch testing to confirm possible allergic contact dermatitis from topical MPH, several test concentrations in the low-to-middle range (such as 0.1%, 1%, and 10%) prepared in petrolatum are advisable.

Background The North American Contact Dermatitis Group (NACDG) tests patients who have suspected allergic contact dermatitis with a broad series of screening allergens, and publishes periodic reports of its data. Objective To report the NACDG patch-test results from January 1, 2005, to December 31, 2006, and to compare results to pooled test data from the previous 10 years. Methods Standardized patch testing with 65 allergens was used at 13 centers in North America. Chi-square statistics were utilized for comparisons with previous NACDG data. Results NACDG patch-tested 4,454 patients; 12.3% (557) had an occupation-related skin condition, and 65.3% (2,907) had at least one allergic patch-test reaction. The 15 most frequently positive allergens were nickel sulfate (19.0%), Myroxilon pereirae (balsam of Peru, 11.9%), fragrance mix I (11.5%), quaternium-15 (10.3%), neomycin (10.0%), bacitracin (9.2%), formaldehyde (9.0%), cobalt chloride (8.4%), methyldibromoglutaronitrile/phenoxyethanol (5.8%), p-phenylenediamine (5.0%), potassium dichromate (4.8%), carba mix (3.9%), thiuram mix (3.9%), diazolidinylurea (3.7%), and 2-bromo-2-nitropropane-1,3-diol (3.4%). As compared to the 1994-2004 data, there were significant increases in rates of positivity to nickel, quaternium-15, potassium dichromate, lidocaine, and tea tree oil. Of patch-tested patients, 22.9% (1,019) had a relevant positive reaction to a supplementary allergen; 4.9% (219) had an occupationally relevant positive reaction to a supplementary allergen. Conclusion Nickel has been the most frequently positive allergen detected by the NACDG; rates significantly increased in the current study period and most reactions were clinically relevant. Other common allergens were topical antibiotics, preservatives, fragrance mix I and paraphenylenediamine. Testing with an expanded allergen series and supplementary allergens enhances detection of relevant positive allergens.

BACKGROUND The prevalence of lanolin sensitivity in referred patients is less than 4%. OBJECTIVES To (1) describe patients with positive patch-test reactions to lanolin, (2) determine clinical and occupational relevance associated with reactions to lanolin and common sources, and (3) examine the frequency of co-reacting allergens. METHODS A retrospective analysis of 26,479 patients patch-tested by the North American Contact Dermatitis Group (NACDG), 1994 to 2006. RESULTS Overall, 2.5% of patients (643 of 25,811) tested to lanolin alcohol 30% in petrolatum had positive reactions. Prevalence decreased from 3.7% in 1996 to 1998 to 1.8% in 2005 to 2006 (p

Background Propylene glycol (PG) may cause allergic or irritant contact dermatitis. It primarily functions as a vehicle, solvent, or emulsifier in cosmetics and topical medications. Objectives To characterize the prevalence of positive patch-test reactions to PG and the epidemiology of affected patients. Methods Retrospective analysis of cross-sectional data compiled by the North American Contact Dermatitis Group (NACDG) from 1996 to 2006. Results Of 23,359 patients, 810 (3.5%) had allergic patch-test reactions to 30% PG; 12.8% of the reactions were of definite clinical relevance (positive reaction to a personal product containing PG), 88.3% were considered to be currently relevant (definite, probable, or possible relevance), and 4.2% of reactions were occupation related, most commonly to mechanical and motor vehicle occupations. Common sources of PG were personal care products (creams, lotions, and cosmetics, 53.8%), topical corticosteroids (18.3%), and other topical medicaments (10.1%). In patients positive only to PG (n = 135), the face was most commonly affected (25.9%), followed by a scattered or generalized pattern (23.7%). The most common concomitant reactions included reactions to Myroxilon pereirae, fragrance mix, formaldehyde, bacitracin, methyldibromoglutaronitrile/phenoxyethanol, carba mix, and tixocortol pivalate. Conclusions In this select population of patients referred for patch testing, allergic reactions to PG were often currently clinically relevant but were rarely related to occupation. The most common sources were personal care products and topical corticosteroids.

BACKGROUND Allergic and irritant contact dermatitis to food is likely underreported. OBJECTIVES To characterize relevant allergens and irritants associated with food in patients referred to the North American Contact Dermatitis Group (NACDG) for patch testing. METHODS Retrospective analysis of cross-sectional data from the NACDG from 2001 to 2004. RESULTS Of 10,061 patch-tested patients, 109 (1.1%) had a total of 122 reactions associated with food. Approximately two-thirds of patients (66%) were female, and one-third (36%) were atopic. The hands were the most common sites of dermatitis (36.7%). There were 78 currently relevant (definite, probable, or possible) allergic reactions to NACDG standard series allergens with a food source; the most common allergen was nickel (48.7%), followed by Myroxilon pereirae (balsam of Peru) (20.6%) and propylene glycol (6.4%). Twenty allergic reactions to non-NACDG standard allergens and 24 relevant food irritants were also identified. Overall, 21% (25 of 122) of all reactions (irritant and allergic) were occupation related; the majority of these (17 of 25) were relevant irritant reactions. Cooks were the most commonly affected occupational group (40%). CONCLUSIONS In this limited data set, nickel, Myroxilon pereirae, and propylene glycol were the most common allergens identified with a food source. Of food-related occupational disease, irritation was more common than allergy.

BACKGROUND Contact dermatoses are common in health care workers (HCWs). OBJECTIVES To (1) estimate the prevalence of occupation-relevant allergic contact dermatitis (ACD) among health care workers patch-tested from 1998 to 2004 by the North American Contact Dermatitis Group (NACDG), (2) characterize responsible allergens among health care workers overall as well as in specific health care occupational subgroups, and (3) compare these results to those of nonhealth care workers. METHODS Between 1998 and 2004, 15,896 patients were patch-tested by the NACDG. Occupation-related allergic patch-test results were analyzed among HCWs, subgroups of HCWs, and non-HCWs. RESULTS 1,255 patients (7.9%) were HCWs. Female gender (HCWs, 86.2%; non-HCWs, 63.6%) and hand involvement (HCWs, 54.7%; non-HCWs, 27.8%) were more common in HCWs (p < .05); 18.2% of HCWs and 6.6% of non-HCWs had occupation-related allergens of current clinical relevance. Thiuram mix (HCWs, 8.87% non-HCWs, 0.90%) and carba mix (HCWs, 5.43%; non-HCWs, 0.87%) were the most common occupation-related currently relevant antigens in HCWs and were more common in HCWs than in non-HCWs (p < .05). CONCLUSIONS Among HCWs patch-tested by the NACDG between 1998 and 2004, the most common allergens were thiuram mix and carba mix, followed by glutaraldehyde, cocamide diethanolamine, and chloroxylenol. Gloves, sterilizing solutions, and soaps were common sources of responsible allergens.

BACKGROUND The most common differential diagnoses for patients presenting with lip dermatitis or inflammation include atopic, allergic, and irritant contact dermatitis. Patch testing can be performed to identify the allergic contact conditions. OBJECTIVE To report North American Contact Dermatitis Group (NACDG) patch-test results of patients who presented for patch testing with only lip involvement from 2001 to 2004. Patient characteristics, allergen frequencies, relevance, final diagnoses, and relevant allergic sources not in the NACDG screening series were evaluated. METHODS The NACDG 2001-2004 database was used to select patients presenting with only lip involvement. RESULTS Of 10,061 patients tested, 2% (n = 196) had lips as the sole involved site. Most (84.2%) were women. After patch testing, 38.3% (n = 75) were diagnosed with allergic contact cheilitis. Fragrance mix, Myroxilon pereirae, and nickel were the most common relevant allergens. Of 75 patients, 27 (36%) had relevant positive patch-test reactions to items not on the NACDG series; lipstick and cosmetics were the predominant sources. CONCLUSIONS Patch testing is valuable in the evaluation and identification of contact allergy in patients referred for lip dermatitis. The use of supplementary allergens based on history and exposure is important in the identification of additional relevant allergens. Over a third of patients with contact allergy had other factors, such as irritant dermatitis, considered relevant to their condition.

BACKGROUND Allergic contact dermatitis from thioureas is uncommon but may result from exposure to rubber, especially neoprene. OBJECTIVES To (1) describe the population with positive patch-test reactions to mixed dialkyl thioureas (MDTU) (ie, diethylthiourea and dibutylthiourea); (2) determine clinical and occupational relevance associated with reactions to MDTU and identify the most commonly related sources and occupations; and (3) examine the frequency of co-reacting allergens in MDTU-positive patients. METHODS A retrospective analysis of cross-sectional data of 22,025 patients patch-tested by the North American Contact Dermatitis Group between 1994 and 2004. RESULTS Of 21,898 patients tested with MDTU, 225 (1.0%) had positive reactions; of these, 173 (76.9%) were currently relevant and 29 (17.1%) were occupationally relevant. Patients positive to MDTU were 2.6 times more likely to have foot involvement than patients with positive reactions to other allergens (p < .0001). Footwear was the most commonly identified source overall (20.0%) whereas gloves were the most common occupational source. Of the 173 patients with currently relevant MDTU reactions, 24.9% also reacted to another rubber allergen. CONCLUSIONS Current clinical relevance of reactions to MDTU was high; occupational relevance was less frequent. Patch tests with common rubber allergens (carbamates, thiurams, and mercaptobenzothiazole) may fail to detect many cases of thiourea-induced rubber allergic contact dermatitis.

BACKGROUND Allergic contact dermatitis is a significant cause of both occupational and non-occupational skin disease. Patch testing is an important diagnostic tool for the determination of responsible allergens. OBJECTIVE This study reports the results of patch testing by the North American Contact Dermatitis Group from January 1, 2003, to December 31, 2004. METHODS At 13 centers in North America, patients were tested with the same screening series of 65 allergens, with a standardized patch-testing technique. Data were recorded on standardized forms and manually verified and entered. Descriptive frequencies were calculated, and trends were analyzed with chi-square statistics. RESULTS A total of 5,148 patients were tested. Of these, 3,432 (66.7%) had at least one positive reaction, 2,284 (44.4%) were ultimately determined to have primary allergic contact dermatitis, and 676 (13.1%) had occupation-related skin disease. There were 9,762 positive allergic reactions. Compared to the previous reporting period (2001-2002), allergies to nickel, budesonide, mercaptobenzothiazole, and paraben mix were at least 1.12 times more common (all p values < .03). Compared with the previous 8 years (1994-2002), only the prevalence rates of allergies to nickel and budesonide were statistically significantly higher (p values < .003). CONCLUSION Allergic contact dermatitis from nickel and budesonide may be increasing in North America. These results again underscore the value of patch-testing with many allergens.

BACKGROUND Allergy to topical anesthetics is not uncommon. The cross-reactivity among topical anesthetics and the screening value of benzocaine alone are not well understood. OBJECTIVES The goals for this study were: (1) to evaluate the frequency and pattern of allergic patch-test reactions to topical anesthetics, using North American Contact Dermatitis Group (NACDG) data, and (2) to compare these results to allergen frequencies from other published studies. METHODS The NACDG patch-tested 10,061 patients between 2001 and 2004. In this analysis patients were included who had positive patch-test reactions to one or more of the following: benzocaine, lidocaine, dibucaine, tetracaine, and prilocaine. RESULTS Of patch-tested patients, 344 (3.4%) had an allergic reaction to at least one anesthetic. Of those, 320 (93.0%) had an allergic reaction to only one topical anesthetic. Overall, reactions to benzocaine (50.0%, 172 of 344) were most prevalent, followed by reactions to dibucaine (27.9%, 96 of 344); however, reactions to dibucaine were significantly more frequent in Canada than in the United States (relative risk [RR], 2.31; 95% confidence interval [CI], 1.67-3.20; p < .0001). Of patients reacting to more than one anesthetic, most (79%, 19 of 24) reacted to both an amide and an ester. CONCLUSIONS Of the topical anesthetics tested, benzocaine was the most frequent allergen overall. Over 50% of allergic reactions to topical anesthetics in this study would have been missed had benzocaine been used as a single screening agent. Cross-reactivity patterns were not consistent with structural groups.

BACKGROUND: Nickel allergy has been studied by contact dermatitis groups around the world, and the frequency of nickel sensitivity has been reported to be decreasing in some populations. OBJECTIVE: To review the prevalence of nickel allergy as observed by the North American Contact Dermatitis Group from 1992 to 2004. METHODS: The computer database of the North American Contact Dermatitis Group was used to examine the prevalence of nickel allergy over the study period and to analyze it by time, sex, and age. RESULTS: From 1992 to 2004, 25,626 patients were patch-tested. The percentage of women tested was fairly constant (61.4-66.3%). A steady increase in nickel sensitivity was seen from 1992 to 2004. Subgroup analysis did not identify a population with declining nickel allergy. CONCLUSIONS: Nickel allergy continues to increase in younger and older men and women patch-tested in North America.

Chemicals used in leather tanning, rubber processing, and/or adhesives are the most often-cited culprits in footwear dermatitis. Patch testing patients with suspected shoe dermatitis is essential for diagnosis and management.The four goals for this study were to (1) determine the frequency of allergens associated with a shoe source in North American Contact Dermatitis Group (NACDG) patients with footwear allergic contact dermatitis; (2) compare these results to allergen frequencies from other published studies; (3) quantify the number of shoe-related reactions that were not identified with the NACDG standard series; and (4) identify relevant allergens not included on the NACDG standard series, based on data from other published studies.The NACDG patch-tested 10,061 patients between 2001 and 2004. Data were retrospectively analyzed by (1) allergen source coded as "shoe," (2) site of dermatitis as "feet," and (3) diagnosis of "allergic contact dermatitis."Among the 109 NACDG patients with allergic contact dermatitis (ACD) of the foot and a shoe source of allergens, p-tertiary butylphenol formaldehyde resin, an adhesive, was the most common allergen, accounting for 24.7% of positive patch-test results, followed by potassium dichromate (17.5%) and carba mix (11.7%). When the data were examined according to groups of allergens, rubber chemicals (40.4%) were the most frequent allergens, followed by adhesives (32.5%), and leather components (20.1%). When data from published studies were pooled, potassium dichromate (31.5%) was the most frequent allergen, followed by p-tertiary butylphenol formaldehyde resin (17.1%) and cobalt chloride (12.9%). NACDG patients were statistically more likely to have positive patch-test reactions to p-tertiary butylphenol formaldehyde resin and statistically less likely to have a positive patch-test reaction to potassium dichromate than patients represented in pooled data from past studies. Nineteen (17.4%) of the 109 NACDG patients with ACD of the foot and a shoe source of allergens were identified as having a shoe source of a relevant allergen not included in the NACDG standard series.In NACDG patients, the most common individual shoe allergen was p-tertiary butylphenol formaldehyde resin. As a group, rubber chemicals were most common, a finding consistent with those of other studies.

BACKGROUND The low concentration of propylene glycol (PG) in pimecrolimus cream makes it unlikely that the cream will induce a PG-related irritant or allergic contact dermatitis. OBJECTIVE To assess reactions to pimecrolimus cream in patients who are allergic to PG. METHODS A pilot double-blind within-patient study in 20 patients, with patch testing followed by a repeated open application test (ROAT). Limitations were that patch tests and ROATs were performed on normal skin, which may be less likely to develop an allergic response than would areas of active dermatitis. RESULTS Positive PG patch-test results were confirmed in 16 patients. Patch-test scores were compatible with allergic reactions in only two patients. However, ROAT scores were negative for these two patients. Reactions with pimecrolimus or vehicle during ROAT were identified in three patients, but an allergic reaction was uncertain because none of these patients reacted with both pimecrolimus cream and vehicle. Reactions with pimecrolimus were significantly less frequent (p

Allergic contact dermatitis can be manifest as an eruption confined to the eyelids. In regard to this specific presentation, only limited information on which to base the selection of patch tests for proper evaluation is available.To identify the contact allergens most frequently found to be both patch test positive and relevant when only the eyelids are involved.Data collected from 2003 to 2004 by the North American Contact Dermatitis Group (NACDG) were analyzed for relevant allergens in the setting of dermatitis on the eyelids only. Data on eyelid dermatitis patients whose relevant allergens were not among the 65 allergens used for screening during this study period were also tabulated.Data showed that 268 patients had only eyelid dermatitis and a final diagnosis of allergic contact dermatitis. In 193 (72%) of these, reactions were of current relevance and were identified from a screening series of 65 allergens. The top 26 allergens identified 65% of cases (175 cases). Gold was the most frequently encountered allergen (22 of 175 cases [12.5%]). Of the 268 cases, 33 showed relevant reactions to an allergen that was not among the 65 NACDG standard screening allergens. No specific allergen was identified in the remaining 42 cases.The top 26 allergens identified in this study represent a potential eyelid dermatitis screening series.

Background In published reports from Europe, 3- and 4-(4-hydroxy-4-methylpentyl)cyclohexene-1-carboxaldehyde (HMPCC) (Lyral) has been described as a common cause of allergic contact dermatitis (ACD). In Europe, the rates of reaction to HMPCC among patients undergoing patch testing for suspected ACD have varied from 1.2 to 17.0%, depending on the country. Data on the incidence of sensitivity to HMPCC among North Americans with suspected ACD have not been reported. Objectives The goals of this study were (1) to assess the incidence of delayed-type hypersensitivity reactions to HMPCC among patients undergoing patch testing for evaluation of eczematous dermatitis at six centers throughout North America; (2) to determine the most appropriate concentration of HMPCC to use in performing patch tests; and (3) to compare and contrast the incidence rates for HMPCC hypersensitivity to those for other fragrance materials screened with the North American Contact Dermatitis Group (NACDG) screening tray, which includes fragrance mix, Myroxilon pereirae (balsam of Peru), cinnamic aldehyde, ylang ylang oil, jasmine absolute, and tea tree oil. Methods This report represents the prospective multicenter data on patients tested with the fragrance-related allergens on the NACDG standard screening tray and with HMPCC at 5%, 1.5%, and 0.5% concentrations in petrolatum. Statistical analyses were performed with Student's t-test (two tailed) and the chi-square test. Results Data from 1,603 patients evaluated at five US sites and one Canadian site were analyzed. Most patients (87.8%) were Caucasian. The majority (67%) were women, and 26.2% had a history consistent with atopic dermatitis. The patients ranged in age from 1 to 88 years, and the mean +/- standard deviation was 46.3 +/- 16.5 years. Myroxilon pereirae (balsam of Peru) and fragrance mix were the most frequent patch-test-positive fragrance allergens (6.6% and 5.9%, respectively). Cinnamic aldehyde (1.7%), ylang ylang oil (0.6%), jasmine absolute (0.4%), HMPCC (0.4% for 5% HMPCC, 0.3% for 1.5% HMPCC, and 0.2% for 0.5% HMPCC), and tea tree oil (0.3%) less frequently yielded positive reactions. Men were more likely than women to be allergic to cinnamic aldehyde. Women were more likely than men to be allergic to jasmine absolute. Atopic patients were no more likely to react to fragrance materials than were nonatopic patients. Patients who reacted to jasmine absolute tended to be older than the general population whereas those who reacted to tea tree oil tended to be younger than the general population. There were no other demographic differences between patients who reacted to a given fragrance material and the entire population studied. Testing with fragrance mix and balsam of Peru failed to identify the majority of patients in this study who were found to be sensitized to jasmine absolute, HMPCC, or tea tree oil. Conclusion HMPCC is an uncommon allergen in the North American population. We recommend testing with 5% HMPCC in petrolatum for those patients suspected of having a fragrance allergy.

Background:Patch testing is the most worthwhile diagnostic tool for the evaluation of patients with suspected allergic contact dermatitis.Objective:This study reports patch-testing results from July 1, 1998, to December 31, 2000, by the North American Contact Dermatitis Group.Methods:Patients were t

Background: The subject of lichen planus (LP) and dental metal allergy long has been debated. An overwhelming majority of the existing literature focuses on mercury and gold salts in relation to oral lichen planus. Objective: Our objective was to expand current knowledge regarding LP and lichenoid lesions (LL) and dental metal allergy by investigating more metals and investigating cutaneous and genital disease in addition to oral disease. Methods: Fifty-one patients with known LP or LL were patch tested to a series of dental metals. Patients chose to replace their dental metals or make no revision. A telephone survey was conducted after 1 year to determine disease state. Results: Thirty-eight of 51 patients (74.5%) had at least 1 positive reaction. Twenty-five of 51 patients (49.0%) showed sensitivity to at least 1 mercurial allergen. Prevalence data for patients patch tested by the North American Contact Dermatitis Group (NACDG) from 1996 to 1998 was available for chromate, cobalt, gold, nickel, and thimerosal. The prevalence of positive reactions was higher in our group than in the NACDG group for all 5 of these allergens, and statistical significance was achieved for chromate (P = .028), gold (P = .041), and thimerosal (P = .005). Of patients who had a positive patch test reaction to 1 or more metals, 100% (9 of 9) reported improvement after metal replacement, whereas 62.5% (15 of 24) reported improvement without metal replacement. Conclusion: Sensitization to dental metals is more common among LP and LL patients than in routinely tested patients, and might be an etiologic or triggering factor in the disease.

Background Allergic contact dermatitis (ACD) is a well-recognized immune-mediated disease often associated with the use of vulcanization accelerator-containing latex and nitrile gloves. Potential contact allergens in neoprene (polychloroisoprene, polychloroprene) gloves have not been reported. Objective The objective was to analyze extracts of neoprene surgical and examination gloves for potential contact allergens. Methods Four different brands of neoprene-type gloves were purchased, and dichloromethane extracts were derivatized and assayed by gas chromatographic mass spectrometry. A latex surgical glove was used as a negative control. Results Chemical species consistent with the composition of disproportionated rosin (dehydroabietic acid [DHA], didehydroabietic acid, and other pimaric or isopimaric species) were identified in dichloromethane extracts of neoprene gloves. Levels of DHA, a type IV prohapten that can be air oxidized to an active allergen, ranged from 7 to 31 mg/g of glove. A leaching study of DHA was conducted, and small amounts of DHA leached from the glove materials into artificial sweat. DHA oxidation products were not observed in any of the gloves assayed. Conclusion DHA exposure may occur from neoprene-type glove use, although a potential association with glove ACD has not been established.

Disulfiram, a nickel chelator, has been reported to be useful in treating hand eczema in some individuals who are allergic to nickel. Nine patients with chronic hand eczema and positive patch tests to nickel completed a 2 month, randomized, double-blind, placebo-controlled, crossover study to evalua