Occupational contact allergy of construction workers in Greece: Trends during 2009-2018.

BACKGROUND: Recent trends in the sensitization of construction workers show a decrease in potassium dichromate and an increase in epoxy resin sensitization. OBJECTIVES: To present the trends of occupational contact allergy of construction workers in Greece from 2009 to 2018. METHODS: We retrospectively reviewed the files of patients with eczema patch tested in our Contact Dermatitis Clinic who were construction workers. RESULTS: A total of 191 construction workers initially reported contact dermatitis. Of these, 138 had occupation-relevant allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD). All patients were men. After being patch tested, 98 (71.0%) were diagnosed with ACD and 40 with ICD. Median duration of occupation till onset of ACD was 2 years (interquartile range [IQR] 0.8-7). The hands were the most common location for ACD (73.5%), followed by the trunk (39.8%), the legs (38.8%), and the face (11.2%). Of the patients, 74.6% had lesions affecting multiple body sites. Potassium dichromate (67%) was the most frequent allergen, followed by thiuram mix (37.4%) and cobalt chloride (31.8%). Sensitization to epoxy resins was lower (12.1%). CONCLUSION: The sensitization pattern of Greek construction workers does not follow the trends in Central or Northern Europe, rather sharing attributes with less industrialized countries.

Contact allergy in a paediatric population observed in a tertiary referral centre in Belgium.

BACKGROUND: Contact allergy is increasingly recognized as being important in children with eczema. OBJECTIVES: To retrospectively analyse the patch test results in children over the past 10 years, aiming to (1) evaluate demographic characteristics and lesion locations, (2) describe frequencies of positive patch test reactions, and (3) investigate the relationship with atopic dermatitis (AD). METHODS: A total of 329 children were patch tested between January 2010 and December 2019 with the European (children) baseline series and/or other series, and the personal product(s) used. RESULTS: A total of 119 (36%) children presented with at least one positive reaction. Children with AD had a higher prevalence of positive reactions compared with the non-AD group (P = .002), but without statistically significant difference regarding sensitization to more than one hapten (P = .39). The face (20.2%), hands (19.3%), feet (16.8%), arms (12.6%), and body folds (10.9%) were the most common sites of primary localizations. The most frequent contact allergens were nickel sulfate and linalool hydroperoxide (both 16%), limonene hydroperoxide (13.5%), and para-phenylenediamine (10.9%). No statistically significant difference for nickel sulfate was found between the AD and non-AD group (P = .20). CONCLUSIONS: Contact allergy in children with eczema was frequently observed in our tertiary referral centre in Belgium as well, confirming the need for patch testing.

Contact Dermatitis in Construction Workers in Northeastern Italian Patch Test Database Between 1996 and 2016.

BACKGROUND: Contact dermatitis in construction workers (CWs) is frequent due to the widespread exposure to sensitizing substances and irritating agents and the wet and cold working conditions. OBJECTIVE: Our objectives were to evaluate contact dermatitis characteristics among CWs who underwent patch test in northeastern Italy and to identify related allergens. METHODS: Seven hundred ninety-five CWs were studied and their data were compared to 2.099 male white-collar workers. The associations between patch test results and occupations were assessed by multivariate logistic regression analysis. Incidence data were calculated from 1996 to 2016. RESULTS: CWs with confirmed occupational dermatitis presented an increased risk to be sensitized to potassium dichromate [OR 3.1 (95%IC 2.0-4.8)], to thiurams [OR 8 .6 (95%IC 4.0-18.4)], and to epoxy resins [OR 12.7 (95%IC 6.1-26.4)]. Sensitization to chromate decreased significantly after 2004, following EU regulation of chromate content in concrete, while sensitization to epoxy resins and thiurams increased. The overall incidence of occupational contact dermatitis in CWs decreased significantly. CONCLUSION: Our study demonstrated the effectiveness of EU regulations in reducing chromate sensitization in CWs and the overall incidence of occupational contact dermatitis. However, sensitization to other haptens is increasing, though improvement of protective measures is compulsory.

Occupational Contact Dermatitis in Hospital Cleaning Workers.

BACKGROUND: Health care workers and hospital cleaning workers are at high risk regarding the development of occupational contact dermatitis (OCD). OBJECTIVES: To determine the prevalence and risk factors of OCD in hospital cleaning workers. METHODS: A questionnaire was conducted in 245 cleaning workers in our cross-sectional study. The 236 cleaning workers formed the study group. In workers who were prediagnosed with dermatitis, physical examination was performed in the Dermatology Outpatient Clinic, and when necessary, patch test, skin biopsy, and investigation for total immunoglobulin E were conducted. Patients with definite contact dermatitis were diagnosed as having OCD by using the Mathias criteria. RESULTS: The prevalence rate of OCD was 21.6% and was significantly higher in female workers (26.4%) when compared with male workers (11.0%). Female sex; low educational level; cleaning the external surfaces of the medical equipment, monitors, and accessories; and mixing the cleaning products and use them while performing cleaning activities were determined as the independent risk factors for OCD. CONCLUSIONS: Occupational contact dermatitis was present at a high rate in hospital cleaning workers. The risk factors should be taken into consideration for prevention of OCD and improvement of the health status of hospital cleaning workers.

Ideal proportion of the population to be patch tested: How many should we be doing?

BACKGROUND: How many patients should we be patch testing? A previous study suggested that the minimum proportion of a population to be patch tested for allergic contact dermatitis was 1:700 annually. OBJECTIVES: To evaluate if the current minimum rate for patch testing has changed over the 20 years since the previous study in order to maximize the value. METHODS: In cooperation with the British Society for Cutaneous Allergy, a proforma for collation of retrospective data between January 2015 and December 2017 was sent to patch-test centers in the United Kingdom (UK) and the Republic of Ireland (ROI). The number of positive tests was analyzed against the proportion of population tested to see what proportion of the population would yield the greatest number of positive results. RESULTS: Responses from 11 centers showed that the minimum number needed to patch test had increased to 1:550 per head of population per year using the current criteria. CONCLUSIONS: In agreement with previous studies, we should be patch testing more people than we are. We could reduce the threshold for referral of patients we patch test to derive the most benefit from this investigation.

Contact Allergy in Canada Versus United States: Analysis of the North American Contact Dermatitis Group Data 2005-2016.

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.

Prevalence of contact allergies in the population compared to a tertiary referral patch test clinic in Jena/Germany.

BACKGROUND: The contact allergy prevalences in patch-tested patients are usually higher than those in the population, owing to morbidity-driven selection. OBJECTIVES: To examine the differences between two samples, one from the population, one from the patch test clinic, in one area of Germany (Jena, Thuringia). METHODS: Between August 2008 and October 2011, a total of 519 participants of the population-based european dermato-epidemiology network (EDEN) fragrance study were patch tested in Jena using a TRUE Test baseline series extended with some pet.-based (fragrance) allergen preparations. Between 2007 and 2012 (inclusive), 1906 routine patients were patch tested for suspected allergic contact dermatitis (ACD) in the Jena University Hospital Department; of these 1694 (83.2%) with the German baseline series using pet./aq.-based, investigator-loaded allergens. RESULTS: In the population (clinical) sample, 19.6% (41.1%) were sensitized to at least one of the allergens considered. The most common baseline series allergens in the population/clinical sample were nickel (10.5%/13.2%), fragrance mix (FM) II (2.9%/6.7%), FM I (2.3%/8.3%), and cobalt (1.6%/5%). The clinical sample was slightly older (71.5% vs 55.9% age 40+) and included less males (36% vs 49.3%). CONCLUSIONS: Results are quite similar, although prevalences are usually higher in the clinical setting, with the exception of p-tert-butylphenol formaldehyde resin.

Should methyldibromo glutaronitrile continue to be used in the European baseline Series? A REIDAC national cross-sectional study.

BACKGROUND: Methyldibromo glutaronitrile (MDBGN) was one of the most frequent and relevant allergens found in patch testing at the beginning of this century. In 2008, this preservative was banned from cosmetics in Europe and ever since the prevalence of contact allergy to MDBGN has progressively decreased. Despite that gradual decline, MDBGN is still patch-tested in most baseline series. This study assessed the frequency of MDBGN sensitization, epidemiological characteristics of allergic patients, and the relevance of positive patch tests in a nationwide Spanish registry (REIDAC). PATIENTS AND METHODS: We evaluated consecutively patch-tested patients in all participating centres. Using these data, we calculated the proportion of patients with positive patch tests to MDBGN from June 2018 to June 2020 and evaluated the relevance of the positive patch tests. RESULTS: One hundred and fourteen out of 5072 (2.24 %) tested patients were sensitized to MDBGN. Clinical current relevance was confirmed in only one case. CONCLUSION: Although the frequency of contact allergy to MDBGN remains high, no clinical significance was found in most of these patients (5072 tests needed to obtain one relevant positive result). The clinical usefulness of this allergen seems weak and its continued inclusion in the European baseline series is questionable.

Patch Testing With a New Composition of the Mercapto Mix-A Multicenter Study from the International Contact Dermatitis Research Group.

BACKGROUND: Mercaptobenzothiazole compounds are associated with allergic contact dermatitis caused by rubber products. Several screening substances have been used for patch testing. OBJECTIVE: To compare the frequency of positive test reactions to a mercapto mix containing a higher concentration of 2-mercaptobenzothiazole with reactions to the combination of 2-mercaptobenzothiazole 2.0% and mercapto mix 2.0%. METHODS: There were 7103 dermatitis patients in 12 International Contact Dermatitis Research Group dermatology departments who were patch tested with 2-mercaptobenzothiazole 2.0% petrolatum (pet.), mercapto mix 2.0% pet., and mercapto mix 3.5% pet. RESULTS: Contact allergy to the 3 test preparations varied among the 12 centers: 2-mercaptobenzothiazole 2.0% pet. (0-2.4%), mercapto mix 2.0% pet. (0-4.9%), and mercapto mix 3.5% pet. (0-1.4%). 2-Mercaptobenzothiazole 2.0% and mercapto mix 2.0% detected a few more positive patients compared with mercapto mix 3.5%, but the difference was statistically insignificant (mercapto mix 2.0% pet., P = 1.0; 2-mercapto-benzothiazole 2.0% pet., P = 0.66). CONCLUSIONS: Mercapto mix 3.5% pet. is not better than 2-mercaptobenzothiazole 2.0% and mercapto mix 2.0% by a difference that is significant. By using only 1 test preparation (mercapto mix 3.5%), an additional hapten could be tested. No cases of suspected/proven patch test sensitization were registered.

Methylchloroisothiazolinone and/or Methylisothiazolinone Contact Allergies in Thailand.

BACKGROUND: Methylchloroisothiazolinone, in combination with methylisothiazolinone (MCI/MI), and MI alone are common preservatives. The incidences of MCI/MI and MI-alone contact allergies have risen markedly worldwide, leading to changes in their use in products. OBJECTIVES: The aim of the study was to determine the incidences of positive patch test reactions and factors associated with MCI and/or MI contact allergies during the recent decade in Thailand. METHODS: Medical records of patients who underwent patch testing at Siriraj Hospital from 2009 to 2018 were retrospectively reviewed. The incidences of positive reactions, histories, and clinical data of MCI/MI and MI-alone contact allergy patients were analyzed. RESULTS: Of 2789 patients undergoing patch testing, most were female (76.1%). The mean ± SD age was 42.7 ± 15.7 years. Positive reactions to MCI/MI increased from 2009 to 2016 before declining. The MCI/MI contact allergy was most common in females, middle-aged patients, and those with metal allergy histories, with the hands and arms being the predominant sites. However, MI-alone contact allergy was more common in males and mainly at the trunk. Its incidence significantly declined for the last 5 years. CONCLUSIONS: The incidences of MCI/MI and MI-alone contact allergies began to decline because the Food and Drug Administration Thailand regulations restricted their use. The risk factors for the allergies reported in this study provide important information for patient care.

Positive Patch Test Reactions to Carba Mix and Thiuram Mix: The North American Contact Dermatitis Group Experience (1994-2016).

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.