Patch testing with maleopimaric acid in an occupational dermatology clinic

Background: Contact allergy to methylisothiazolinone (MI) or to the combination of methylchloroisothiazolinone and MI (MCI/MI) is an important and increasing cause of allergic contact dermatitis, with prevalence rates higher than 10% in some centers. Objectives: The objective of this retrospective chart review is to provide a western Canadian perspective on whether the positive patch testing rate to MCI/MI or MI increased during the testing period of 2008 to 2015 and whether the addition of MI at 2000 ppm resulted in increased detection. Methods: We conducted a retrospective chart review of patients who tested positive (n = 104) of 2177 total patients who were patch tested for MCI/MI or MI at a community dermatology clinic in Vancouver, British Columbia, Canada, from January 2008 through April 2015. Results: One hundred and four patients had positive patch testing results for MCI/MI, MI, or both. Positive results increased over the study period, with the highest prevalence in 2015 at 9.41% for MCI/MI, 12.94% for MI, and 15.29% for either. When testing for MI at 2000 ppm was introduced in 2013, the initial positive patch testing prevalence was 6.6%, followed by 10.1% in 2014, and 12.9% in 2015. Conclusions: We demonstrate an increasing prevalence of MCI/MI and MI allergy between 2008 and 2015, with the highest prevalence of 15.29% in 2015 for MCI/MI and/or MI allergy. The addition of MI 2000 ppm greatly increased the positive patch testing yield for MI. Our results support the importance of continued efforts to monitor and regulate these preservatives.

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P.2.04 Occupational skin disease in a tertiary occupational dermatologic clinic: a retrospective analysis from 2010 to 2017

Occupational and Environmental Medicine ◽

10.1136/oem-2019-epi.240 ◽

2019 ◽

Vol 76 (Suppl 1) ◽

pp. A88.2-A88

Author(s):

Heng-Hao Chang ◽

Bour-Jr Wang ◽

How-Ran Guo ◽

I-Ru Lee

Keyword(s):

Contact Dermatitis ◽

Patch Testing ◽

Skin Disease ◽

Skin Diseases ◽

Potassium Dichromate ◽

University Hospital ◽

Occupational Skin Disease ◽

Duration Of Symptoms ◽

Dermatology Clinic ◽

Patient Reported

BackgroundOccupational skin disease (OSD) is one of the most common occupational disorders in Taiwan. As reporting OSD was not compulsory, there was limited information on the exact causes and patient characteristics. The objective of this study was to investigate the causes and common allergens among OSD patients in Taiwan.MethodsWe recruited patients from Occupational Dermatology Clinic in National Cheng Kung University Hospital, a tertiary referral center in Tainan city, between 1 January 2010 and 31 July 2017. Patch testing with European baseline series, additional occupation-oriented series, and personal material exposed at work or during daily life was carried out if the patients were suspected of allergic skin diseases.ResultsAmong the 273 patients who received patch testing, 51 (18.7%) patients had a final diagnosis of OSD. 82.4% of the 51 patients were diagnosed with allergic contact dermatitis (ACD), 11.8% with irritant contact dermatitis (ICD), while the rest 5.9% with both. Patient reported 3.0 years of skin problem prior to the clinic visit. The vast majority of patients suffered from hand eczema. Epoxy resin workers, food workers, hairdressers and beauty salon beauticians were the most common occupations related to OSD. The most important allergens were nickel, fragrance mix I, potassium dichromate and paraben mix. Around half of the patients showed allergic reaction to their personal material.DiscussionAs worker compensation statistics may not accurately estimate the characteristics of OSD patients, our study was crucial to identify the high-risk groups as well as the common allergens related to their work. Although the results might not represent the proportion of patients of OSD in other clinic, drawing information from patch testing may reflect those patients of severer or longer duration of symptoms. Future occupational measures should be taken on these industries for the detection and prevention of OSD.

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