Custom Allergen Testing Boosts Occupational Dermatitis Diagnoses

NEW ORLEANS – Custom patch testing is worthwhile as an adjunct to standard evaluation to identify allergens causing occupational dermatitis, according to a study of more than 100 patients that was presented at the annual meeting of the American Contact Dermatitis Society.

The investigators discovered new allergens for these patients and confirmed others based on patch testing with workplace materials including chemicals, protective equipment, skin care products, and other materials.

Of 113 employees who were custom patch tested at the Occupational Disease Specialty Program at St. Michael's Hospital in Toronto, 24% had a positive reaction to at least one allergen.

Dr. D. Linn Holness and her associates showed that custom testing identified the culprit that caused dermatitis for 12% of patients when standard tests were negative. In addition, a custom approach confirmed a suspected allergen in another 12% of patients.

Custom patch testing, therefore, adds diagnostic value to conventional standard tests, Dr. Holness said.

"Knowing the specific product helps when returning the person to the workplace – knowing they have to avoid one paint coating, for example," said Dr. Holness, chair of the department of occupational and environmental health at the University of Toronto.

The 113 workers were among a total of 753 manufacturing and automotive industry employees who were patch tested in 2002-2009. (The majority received standard allergen screening.) Their mean age was 44 years, and 63% were men. Glues, adhesives, wood dust, foam dust, wood, spices, and workplace skin care products were among the materials evaluated.

Most case reports in the literature use occlusion, but open and semiopen custom patch testing also are reported. There is little consensus in the literature overall regarding the ideal method or methods for performing this testing, however. Dr. Holness noted that "our dermatologists were using a variety of different methods."

Dr. Holness said she was pleased that the custom testing added value to the clinical diagnoses for these workers. "We did this study to support the custom testing," she said. "We got challenged by some of our occupational medicine colleagues claiming our testing methods were not appropriate, were hazardous, and we shouldn't be doing this. They took it to our workman's compensation board."

Dr. Holness said that she had no relevant disclosures.

NEW ORLEANS – Custom patch testing is worthwhile as an adjunct to standard evaluation to identify allergens causing occupational dermatitis, according to a study of more than 100 patients that was presented at the annual meeting of the American Contact Dermatitis Society.

The investigators discovered new allergens for these patients and confirmed others based on patch testing with workplace materials including chemicals, protective equipment, skin care products, and other materials.

Of 113 employees who were custom patch tested at the Occupational Disease Specialty Program at St. Michael's Hospital in Toronto, 24% had a positive reaction to at least one allergen.

Dr. D. Linn Holness and her associates showed that custom testing identified the culprit that caused dermatitis for 12% of patients when standard tests were negative. In addition, a custom approach confirmed a suspected allergen in another 12% of patients.

Custom patch testing, therefore, adds diagnostic value to conventional standard tests, Dr. Holness said.

"Knowing the specific product helps when returning the person to the workplace – knowing they have to avoid one paint coating, for example," said Dr. Holness, chair of the department of occupational and environmental health at the University of Toronto.

The 113 workers were among a total of 753 manufacturing and automotive industry employees who were patch tested in 2002-2009. (The majority received standard allergen screening.) Their mean age was 44 years, and 63% were men. Glues, adhesives, wood dust, foam dust, wood, spices, and workplace skin care products were among the materials evaluated.

Most case reports in the literature use occlusion, but open and semiopen custom patch testing also are reported. There is little consensus in the literature overall regarding the ideal method or methods for performing this testing, however. Dr. Holness noted that "our dermatologists were using a variety of different methods."

Dr. Holness said she was pleased that the custom testing added value to the clinical diagnoses for these workers. "We did this study to support the custom testing," she said. "We got challenged by some of our occupational medicine colleagues claiming our testing methods were not appropriate, were hazardous, and we shouldn't be doing this. They took it to our workman's compensation board."

Dr. Holness said that she had no relevant disclosures.

NEW ORLEANS – Custom patch testing is worthwhile as an adjunct to standard evaluation to identify allergens causing occupational dermatitis, according to a study of more than 100 patients that was presented at the annual meeting of the American Contact Dermatitis Society.

The investigators discovered new allergens for these patients and confirmed others based on patch testing with workplace materials including chemicals, protective equipment, skin care products, and other materials.

Of 113 employees who were custom patch tested at the Occupational Disease Specialty Program at St. Michael's Hospital in Toronto, 24% had a positive reaction to at least one allergen.

Dr. D. Linn Holness and her associates showed that custom testing identified the culprit that caused dermatitis for 12% of patients when standard tests were negative. In addition, a custom approach confirmed a suspected allergen in another 12% of patients.

Custom patch testing, therefore, adds diagnostic value to conventional standard tests, Dr. Holness said.

"Knowing the specific product helps when returning the person to the workplace – knowing they have to avoid one paint coating, for example," said Dr. Holness, chair of the department of occupational and environmental health at the University of Toronto.

The 113 workers were among a total of 753 manufacturing and automotive industry employees who were patch tested in 2002-2009. (The majority received standard allergen screening.) Their mean age was 44 years, and 63% were men. Glues, adhesives, wood dust, foam dust, wood, spices, and workplace skin care products were among the materials evaluated.

Most case reports in the literature use occlusion, but open and semiopen custom patch testing also are reported. There is little consensus in the literature overall regarding the ideal method or methods for performing this testing, however. Dr. Holness noted that "our dermatologists were using a variety of different methods."

Dr. Holness said she was pleased that the custom testing added value to the clinical diagnoses for these workers. "We did this study to support the custom testing," she said. "We got challenged by some of our occupational medicine colleagues claiming our testing methods were not appropriate, were hazardous, and we shouldn't be doing this. They took it to our workman's compensation board."

Dr. Holness said that she had no relevant disclosures.