Joseph F. Fowler

North American Contact Dermatitis Group patch test results for the detection of delayed-type hypersensitivity to topical allergens

BACKGROUND Allergic contact dermatitis is a significant cause of cutaneous disease affecting many individuals. Patch testing, when used properly, often provides support for the diagnosis of allergic contact dermatitis. OBJECTIVE This article reports patch testing results from July 1, 1994, to June 30, 1996, by the North American Contact Dermatitis Group (NACDG). METHODS Patients evaluated in our patch test clinics were tested with the same screening series of allergens by the use of a standardized patch testing technique. The data from these patients were recorded on a standard computer entry form and analyzed. RESULTS Forty-nine allergens were tested on 3120 patients. Budesonide was added to the series in July 1995 and tested on 1678 patients. Of these patients, 66.5% had positive allergic patch test reactions, and 57% had at least one allergic reaction that was felt to be clinically relevant to the present or past dermatitis. The 20 screening allergens commercially available to United States dermatologists in the Allergen Patch Test Kit, accounted for only 54.1% of the patients with positive allergic reactions. The additional 30 allergens on the NACDG screening series accounted for 47% of patients with positive allergic reactions. Had the Allergen Patch Test Kit alone been used, 12.4% of all patients tested may have had their disease misclassified as a nonallergic disorder, and an additional 34.4% of all tested patients would not have had their allergies fully defined. Among those patients with positive responses to the supplemental allergens, 81% of the responses were of present or past relevance. The 12 most frequent contact allergens were nickel sulfate, fragrance mix, thimerosal, quaternium-15, neomycin sulfate, formaldehyde, bacitracin, thiuram mix, balsam of Peru, cobalt chloride, para-phenylenediamine, and carba mix. The present relevance varied with the specific allergen from 10.7% (thimerosal) to 85.7% (quaternium-15). Among newer allergens, methyldibromoglutaronitrile/phenoxyethanol (cosmetic preservative) caused positive allergic reactions in 2% of the patients; tixocortol-21-pivalate and budesonide (corticosteroids), in 2.0% and 1.1% of the patients, respectively; and ethylene urea/melamine formaldehyde mix (textile resin), in 5% of the patients. CONCLUSION The usefulness of patch testing is enhanced with the number of allergens tested, because allergens not found on the commercially available screening series in the United States frequently give relevant allergic reactions.

North American Contact Dermatitis Group patch-test results, 2001-2002 study period.

Background: Allergic contact dermatitis is a significant cause of cutaneous disease affecting many individuals in the home and at the workplace. Patch testing is the most worthwhile diagnostic tool for the evaluation of patients with suspected allergic contact dermatitis. Objective: This study reports the results of patch testing from January 1, 2001, to December 31, 2002, by the North American Contact Dermatitis Group (NACDG). Methods: Patients were tested with an extended screening series of 65 allergens. A standardized patch‐testing technique was used. Data from these patients were recorded on a standardized computer entry form and analyzed. Results: Sixty‐five allergens were tested on 4,913 patients. The top 10 allergens remain the same in this study period as in the 1999‐2000 study period: nickel sulfate (16.7%), neomycin (11.6%), Myroxilon pereirae (balsam of Peru) (11.6%), fragrance mix (10.4%), thimerosal (10.2%), sodium gold thiosulfate (10.2%), quaternium‐15 (9.3%), formaldehyde (8.4%), bacitracin (7.9%), and cobalt chloride (7.4%). Of the 4,913 patients tested, 69% had at least one positive allergic patch‐test reaction. Of all patients, 15.8% had occupation‐related dermatitis; 15.4% were determined to have irritant contact dermatitis, and 11.1% of the 15.4% had a relevant reaction to an occupational irritant. Of all patients tested, 16.7% had a relevant reaction to an allergen not in the NACDG standard series, and 5.5% had a relevant reaction to an occupational allergen not in the standard series. Conclusion: Our findings once again reinforce the need for a more comprehensive group of diagnostic allergens than those found in the standard screening kits. The usefulness of patch testing is enhanced when a greater number of allergens are tested, especially nonstandard allergens occupationally encountered.

Patch-test results of the North American Contact Dermatitis Group 2005-2006.

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 significantlyincreased 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.

North American Contact Dermatitis Group Patch-test Results, 1998 to 2000

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 tested with the same screening series of allergens, using a standardized patch-testing technique. The data from these patients were recorded on a standard computer entry form and analyzed. RESULTS Fifty allergens were tested on over 5,800 patients. Amidoamine, benzophenone-3, and iodopropynyl butylcarbamate were the new allergens. The top 10 allergens in frequency of positive reactions were identical to those of our 1996-to 1998-study period. The incidence of allergic nickel reactions continues to go up, leading all the test substances by 16.2%. CONCLUSION Our findings reinforce the need for a more comprehensive group of diagnostic allergens than is found in the T.R.U.E. TEST, which is sold in the United States.

The impact of psoriasis on health care costs and patient work loss.

BACKGROUND There are few comprehensive estimates of the cost of psoriasis in the United States. OBJECTIVE We sought to quantify the incremental direct medical and indirect work loss costs associated with psoriasis. METHODS A de-identified claims database from 31 self-insured employers during the period 1998 to 2005 was used. Patients with at least two psoriasis diagnosis claims (N = 12,280) were compared with 3 control subjects (matched on year of birth and sex) without psoriasis. Multivariate two-part regression analysis was used to isolate the incremental cost of psoriasis by controlling for comorbidities and other confounding factors. RESULTS After multivariate adjustment, the incremental direct and indirect costs of psoriasis were approximately

North American Contact Dermatitis Group patch test results: 2009 to 2010.

900 and

North American contact dermatitis group patch test results: 2011-2012.

600 (P < .001) per patient per year, respectively. LIMITATIONS The database used in this study does not contain information on patient out-of-pocket costs or loss of productivity costs at work. CONCLUSION The incremental cost of psoriasis is approximately

Prevention of poison ivy and poison oak allergic contact dermatitis by quaternium-18 bentonite☆

1500 per patient per year, with work loss costs accounting for 40% of the cost burden.

North American Contact Dermatitis Group patch test results for 2007-2008.

Background Patch testing is an important diagnostic tool for determination of substances responsible for allergic contact dermatitis. Objective This study reports the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2009, to December 31, 2010. Methods At 12 centers in North America, patients were tested in a standardized manner with a screening series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends were analyzed using &khgr;2 statistics. Results A total of 4308 patients were tested. Of these, 2614 (60.7%) had at least 1 positive reaction, and 2284 (46.3%) were ultimately determined to have a primary diagnosis of allergic contact dermatitis. Four hundred twenty-seven (9.9%) patients had occupationally related skin disease. There were 6855 positive allergic reactions. As compared with the previous reporting period (2007–2008), the positive reaction rates statistically decreased for 20 allergens (nickel, neomycin, Myroxylon pereirae, cobalt, formaldehyde, quaternium 15, methydibromoglutaronitrile/phenoxyethanol, methylchlorisothiazolinone/methylisothiazolinone, potassium dichromate, diazolidinyl urea, propolis, dimethylol dimethylhydantoin, 2-bromo-2-nitro-1,3-propanediol, methyl methacrylate, ethyl acrylate, glyceryl thioglycolate, dibucaine, amidoamine, clobetasol, and dimethyloldihydroxyethyleneurea; P < 0.05) and statistically increased for 4 allergens (fragrance mix II, iodopropynyl butylcarbamate, propylene glycol, and benzocaine; P < 0.05). Approximately one quarter of tested patients had at least 1 relevant allergic reaction to a non-NACDG allergen. Hypothetically, approximately one quarter of reactions detected by NACDG allergens would have been missed by TRUE TEST (SmartPractice Denmark, Hillerød, Denmark). Conclusions These results affirm the value of patch testing with many allergens.

North American Contact Dermatitis Group patch-test results, 2003-2004 study period

BackgroundPatch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). ObjectiveThis study documents the North American Contact Dermatitis Group (NACDG) patch-testing results from January 1, 2011, to December 31, 2012. MethodsAt 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 &khgr;2 statistics. ResultsFour 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, Hillerød, Denmark). ConclusionsThese 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.