Contact dermatitis is a frequent skin disorder related to environmental and occupational etiological factors, which could potentially affect all age groups, as well as both genders. The current study is aimed at exploring the patterns of contact sensitization with respect to the population’s occupational patterns in Greece. A retrospective analysis was performed in a cohort of 1978 patients from 2014 to 2016. Patients were divided into two categories; blue collars (BlC) and white collars (WhC), as well as detailed occupation was considered. Separation was performed on the basis of their profession, i.e., labor workers and handicraftsmen were sorted to the BlC group, while office employees were sorted to the WhC group. The common allergen in all occupational subgroups was nickel sulphate. The three most prevalent allergens in both BlC and WhC were nickel sulphate 5%, fragrance mix (I) 8%, and Balsam of Peru 25%. WhC males were uniquely sensitized to colophony 20% and formaldehyde 2%, and WhC females were uniquely sensitized to 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and neomycin sulphate 20%. Sensitization to allergens manifested occupation-specific patterns. Allergic contact dermatitis surveillance is of great importance towards the clinical and systematic understanding of the disease, especially with respect to the patient’s occupational profile.
Occupational dermatitis (OD) is defined as “skin, mucous and attachments changes directly or indirectly caused, conditioned, maintained or aggravated in professional activity or work environment” [
In the present study, we have attempted to report the pattern of contact sensitization, with respect to the occupational profile of a Greek patient cohort, through patch testing against a large number of allergens inducing contact dermatitis. To the best of our knowledge, this is the first report concerning this topic.
A total number of 1978 Greek Caucasian patients (619 M/1359F) were admitted in our laboratory during the period between 2014 and 2016 (total of three years). Patients were recruited based on their dermatological profile, whereas all other biometric and anthropometric criteria were kept random. The mean age of all patients was
Patient population and age (¥
Population | ||||
Males ( | Females ( | Sum | ||
2014 | 211 | 457 | 668 | |
2015 | 201 | 453 | 654 | |
2016 | 207 | 449 | 656 | |
Sum | 619 | 1359 | 1978 | |
Age (years) ( | ||||
Males | Females | Both genders | ||
2014 | 0.59 | |||
2015 | 0.002 | |||
2016 | 0.73 | |||
All years | 0.02 |
Patients suspected for dermatitis were included in the present study after going through admittance and diagnosis in our department [
The patch testing procedure has been previously described in detail [
Patients admitted in our department, as well as included in the present study, underwent a clinical evaluation, which entailed the collection of routine data. Data included the collection of demographic, clinical data, and patch testing results related to patients suspected with allergic contact dermatitis, as well as occupation. The results were documented to an electronic database. In the case of the patient’s repeated admittance, during our study period, only the initial patch test result was considered as previously described [
Patient’s characteristics are presented with absolute and relative frequencies (%) [
For comparisons between groups, one-way analysis of variance (ANOVA) was performed for the continuous variables, and Chi-square tests were used for the categorical variables. Post hoc comparisons (adjusted with Bonferroni criterion) were also performed when significant differences (
The protocol of our study was approved by the Institutional Scientific Review Board of the University Hospital “
As aforementioned, we have separated our population in two main occupational categories: blue collars (BlC) and white collars (WhC) (for professions included in each category, please refer to Supplementary Table
From our results, it appeared that the most prevalent allergen was nickel sulphate 5% (7.33%, 23.58%), followed by other allergens in the following descending order: fragrance mix (I) 8% (3.99%, 12.85%), Balsam Of Peru 25% (2.43%, 7.80%), potassium dichromate 0.5% (2.22%, 7.15%), cobalt chloride 1% (2.07%, 6.67%), paraphenylenediamine 1% (2.02%, 6.50%), ethylenediamine 1% (1.57%, 5.04%), thiomersal 0.1% (1.42%, 4.55%), thiuram mix 1% (1.31%, 4.23%), budesonide 0.01% (0.86%, 2.76%), formaldehyde 2% (0.76%, 2.44%), colophony 20% (0.71%, 2.28%), CMIT (0.66%, 2.11%), Neomycin sulphate 20% (0.66%, 2.11%), and wool alcohols 30% (0.46%, 1.46%) (Table
Frequencies of the top-15 allergens of the EBS. Frequencies are presented in descending order calculated with respect to the BlC population (
Blue collars ( | |||||||||
---|---|---|---|---|---|---|---|---|---|
All blue collars | Males ( | Females ( | |||||||
Absolute frequency | Absolute frequency | Absolute frequency | |||||||
Nickel sulphate 5% | 145 | 7.33% | 23.58% | 21 | 1.06% | 13.46% | 124 | 6.27% | 27.02% |
Fragrance mix (I) 8% | 79 | 3.99% | 12.85% | 13 | 0.66% | 8.33% | 66 | 3.34% | 14.38% |
Balsam of Peru 25% | 48 | 2.43% | 7.80% | 16 | 0.81% | 10.26% | 32 | 1.62% | 6.97% |
Potassium dichromate 0.5% | 44 | 2.22% | 7.15% | 25 | 1.26% | 16.03% | 19 | 0.96% | 4.14% |
Cobalt chloride 1% | 41 | 2.07% | 6.67% | 20 | 1.01% | 12.82% | 21 | 1.06% | 4.58% |
Paraphenylenediamine 1% | 40 | 2.02% | 6.50% | 11 | 0.56% | 7.05% | 29 | 1.47% | 6.32% |
Ethylenediamine 1% | 31 | 1.57% | 5.04% | 12 | 0.61% | 7.69% | 19 | 0.96% | 4.14% |
Thiomersal 0.1% | 28 | 1.42% | 4.55% | 13 | 0.66% | 8.33% | 15 | 0.76% | 3.27% |
Thiuram mix 1% | 26 | 1.31% | 4.23% | 13 | 0.66% | 8.33% | 13 | 0.66% | 2.83% |
Budesonide 0.01% | 17 | 0.86% | 2.76% | 6 | 0.30% | 3.85% | 11 | 0.56% | 2.40% |
Formaldehyde 2% | 15 | 0.76% | 2.44% | 5 | 0.25% | 3.21% | 10 | 0.51% | 2.18% |
Colophony 20% | 14 | 0.71% | 2.28% | 3 | 0.15% | 1.92% | 11 | 0.56% | 2.40% |
CMIT | 13 | 0.66% | 2.11% | 5 | 0.25% | 3.21% | 8 | 0.40% | 1.74% |
Neomycin sulphate 20% | 13 | 0.66% | 2.11% | 3 | 0.15% | 1.92% | 10 | 0.51% | 2.18% |
Wool alcohols 30% | 9 | 0.46% | 1.46% | 4 | 0.20% | 2.56% | 5 | 0.25% | 1.09% |
In the case of male BlC, it appeared that the most prevalent allergen was potassium dichromate 0.5% (1.26%, 16.03%), nickel sulphate 5% (1.06%, 13.46%), cobalt chloride 1% (1.01%, 12.82%), Balsam of Peru 25% (0.81%, 10.26%), thiomersal 0.1% (0.66%, 8.33%), fragrance mix (I) 8% (0.66%, 8.33%), thiuram mix 1% (0.66%, 8.33%), ethylenediamine 1% (0.61%, 7.69%), paraphenylenediamine 1% (0.56%, 7.05%), budesonide 0.01% (0.30%, 3.85%), epoxy resin 1% (0.30%, 3.85%), CMIT (0.25%, 3.21%), formaldehyde 2% (0.25%, 3.21%), wool alcohols 30% (0.20%, 2.56%), and benzocaine 5% (0.20%, 2.56%) (Table
Similarly, for the female BlC, it appeared that the most prevalent allergen was nickel sulphate 5% (6.27%, 27.02%), fragrance mix (I) 8% (3.34%, 14.38%), Balsam of Peru 25% (1.62%, 6.97%), paraphenylenediamine 1% (1.47%, 6.32%), cobalt chloride 1% (1.06%, 4.58%), ethylenediamine 1% (0.96%, 4.14%), potassium dichromate 0.5% (0.96%, 4.14%), thiomersal 0.1% (0.76%, 3.27%), thiuram mix 1% (0.66%, 2.83%), budesonide 0.01% (0.56%, 2.40%), colophony 20% (0.56%, 2.40%), formaldehyde 2% (0.51%, 2.18%), Neomycin sulphate 20% (0.51%, 2.18%), CMIT (0.40%, 1.74%), quaternium 15 1% (0.30%, 1.31%), paratertiary butyl phenol 1% (0.30%, 1.31%), and wool alcohols 30% (0.25%, 1.09%) (Table
Frequencies are presented in brackets with respect to the total population as well as with respect to the subpopulation under investigation. Thus, in the present case, frequencies are calculated with respect to the total population (
Frequencies of the top-15 allergens of the EBS. Frequencies are presented in descending order calculated with respect to the WhC population (
White collars ( | |||||||||
---|---|---|---|---|---|---|---|---|---|
All white collars | Males ( | Females ( | |||||||
Absolute frequency | Absolute frequency | Absolute frequency | |||||||
Nickel sulphate 5% | 367 | 18.55% | 26.93% | 47 | 2.38% | 10.15% | 320 | 16.18% | 35.56% |
Fragrance mix (I) 8% | 202 | 10.21% | 14.82% | 59 | 2.98% | 12.74% | 143 | 7.23% | 15.89% |
Balsam of Peru 25% | 145 | 7.33% | 10.64% | 62 | 3.13% | 13.39% | 83 | 4.20% | 9.22% |
Thiomersal 0.1% | 113 | 5.71% | 8.29% | 35 | 1.77% | 7.56% | 78 | 3.94% | 8.67% |
Cobalt chloride 1% | 108 | 5.46% | 7.92% | 24 | 1.21% | 5.18% | 84 | 4.25% | 9.33% |
Ethylenediamine 1% | 70 | 3.54% | 5.14% | 33 | 1.67% | 7.13% | 37 | 1.87% | 4.11% |
Potassium dichromate 0.5% | 67 | 3.39% | 4.92% | 25 | 1.26% | 5.40% | 42 | 2.12% | 4.67% |
Paraphenylenediamine 1% | 57 | 2.88% | 4.18% | 6 | 0.30% | 1.30% | 51 | 2.58% | 5.67% |
Neomycin sulphate 20% | 44 | 2.22% | 3.23% | 9 | 0.46% | 1.94% | 35 | 1.77% | 3.89% |
CMIT | 43 | 2.17% | 3.15% | 7 | 0.35% | 1.51% | 36 | 1.82% | 4.00% |
Formaldehyde 2% | 43 | 2.17% | 3.15% | 13 | 0.66% | 2.81% | 30 | 1.52% | 3.33% |
Budesonide 0.01% | 38 | 1.92% | 2.79% | 18 | 0.91% | 3.89% | 20 | 1.01% | 2.22% |
Colophony 20% | 27 | 1.37% | 1.98% | 14 | 0.71% | 3.02% | 13 | 0.66% | 1.44% |
Black rubber mix 0.1% | 24 | 1.21% | 1.76% | 4 | 0.20% | 0.86% | 20 | 1.01% | 2.22% |
Wool alcohols 30% | 21 | 1.06% | 1.54% | 9 | 0.46% | 1.94% | 12 | 0.61% | 1.33% |
Frequencies are presented in brackets with respect to the total population as well as with respect to the subpopulation under investigation. Thus, in the present case, frequencies are calculated with respect to the total population (
Frequencies are presented in brackets with respect to the total population as well as with respect to the subpopulation under investigation. Thus, in the present case, frequencies are calculated with respect to the total population (
If we examine Tables
In the present analysis, we have estimated the total positive allergens in each subgroup, thus, with respect to gender and occupation. Total allergens were estimated by counting the allergens in which each patient manifested a positive test and then these data were compared with respect to gender and occupation. Hence, significant differences were observed between female WhC and male WhC (
Age and number of total positive allergens with respect to gender and occupation. Significant differences were observed between female WhC (
Risk measures, with respect to occupation, manifested several interesting results. In particular, occupational dermatitis showed that the BlC group was 80% more likely to have preexisting occupational exposure (OE) than the WhC group (
Risk ratios of patients with respect to their occupation, as compared to other dermatological factors (Legend: OD: occupational dermatitis; HD: hand dermatitis; FD: lower extremities dermatitis; TD: trunk dermatitis, >2 SITES: patients that manifested more than two concurrent positive sites of dermatitis; Fhist: familial history of atopy; OR: odds ratio; RR: relative risk; AR: absolute risk).
Odds ratio (OR) | Fishers test | |||
---|---|---|---|---|
Occupational dermatitis | OD_NO | OD_YES | 4.9098 | |
White collar | 1083 | 280 | ||
Blue collar | 271 | 344 | ||
Hand dermatitis | HD_NO | HD_YES | 1.7254 | |
White collar | 736 | 627 | ||
Blue collar | 249 | 366 | ||
Face dermatitis | FD_NO | FD_YES | 0.7686 | 0.0141 |
White collar | 908 | 455 | ||
Blue collar | 444 | 171 | ||
Leg dermatitis | LD_NO | LD_YES | 0.6448 | 0.0002 |
White collar | 999 | 364 | ||
Blue collar | 498 | 117 | ||
Trunk dermatitis | TD_NO | TD_YES | 0.6705 | 0.0003 |
White collar | 915 | 448 | ||
Blue collar | 463 | 152 | ||
Dermatitis in more than 2 sites | >2_SITES_NO | >2_SITES_YES | 0.7488 | 0.0259 |
White collar | 1085 | 278 | ||
Blue collar | 516 | 99 | ||
Familial history | Fhist_YES | Fhist_NO | 1.5206 | 0.0017 |
White collar | 276 | 1087 | ||
Blue collar | 88 | 527 | ||
Thiuram mix 1% | Negative | Positive | 2.8209 | 0.0006 |
White collar | 1342 | 21 | ||
Blue collar | 589 | 26 | ||
Balsam of Peru 25% | Negative | Positive | 0.7111 | 0.0498 |
White collar | 1218 | 145 | ||
Blue collar | 567 | 48 | ||
Epoxy resin 1% | Negative | Positive | 3.5796 | 0.0301 |
White collar | 1358 | 5 | ||
Blue collar | 607 | 8 | ||
Thiomersal 0.1% | Negative | Positive | 0.5277 | 0.0024 |
White collar | 1250 | 113 | ||
Blue collar | 587 | 28 | ||
Abiet acid 10% | Negative | Positive | 6.5463 | 0.0001 |
White collar | 202 | 6 | ||
Blue collar | 72 | 14 | ||
Ammonium persulfate 2.5% | Negative | Positive | 7.0085 | 0.0030 |
White collar | 205 | 3 | ||
Blue collar | 78 | 8 | ||
D. pteronyssinus | Negative | Positive | 0.2593 | 0.0039 |
White collar | 168 | 40 | ||
Blue collar | 81 | 5 | ||
D. farinae | Negative | Positive | 0.2785 | 0.0162 |
White collar | 177 | 31 | ||
Blue collar | 82 | 4 |
Finally, in Supplementary Table
The present study has attempted to report and analyze the prevalence of contact sensitization in a Greek patient cohort with respect to the occupational status of our patient cohort. We have separated our patient cohort in two main categories, based on their occupational status, which was BlC and WhC. Our results manifested that contact sensitization was prevalent in both occupational subgroups as well as with respect to gender and occupational group. The investigation of sensitization profiles based on the occupational profiles of a patient cohort can possibly assist towards the identification of the possible sources of sensitization in terms of habitual circumstances or lifestyles. For example, in our study, the anticipated sensitization to fragrance mix was due to the use of cosmetics, as it appeared that it was more frequent to white collars [
In the present work, we have found that nickel sulphate 5% is the most prevalent allergen in all occupational subgroups, the general population, which is in agreement with previous reports [
Another interesting finding was that WhC and BlC manifested a reversed pattern with respect to age. In particular, male WhC patients were older as compared to females WhC, and the opposite was manifested for BlC, where female BlC were older as compared to male BlC. To the best of our knowledge, there are no previous reports for the Greek population. In addition, another interesting finding was the fact that female WhC manifested significantly higher positive allergens as compared to male WhC and female BlC, yet the same as compared to male BlC. It would be expected that BlC due to their occupational profiles should manifest more positive allergens as compared to WhC. This result indicates that sensitization includes more factors than the mere immunological response to allergens. To the best of our knowledge, there are no previous reports on this finding.
Further on, the finding that the BlC group was 80% more likely to have preexisting occupational exposure (OE) as compared to the WhC group agreed with the separation of our cohort between “hand workers” and “clerks.” Similarly, BlC were more prone to upper extremities preexisting dermatitis, supporting the classification of our cohort, also indicating that the occupational profile of a patient cohort could prove useful towards the prediction and prevention of allergens. This was also supported by the finding that WhC were more prone to preexisting facial dermatitis as compared to BlC. In addition, the identification of unique “sensitizers” for each of the occupational groups could prove useful for the prevention of contact dermatitis, besides the already known most prevalent allergens. In many cases, sensitization takes place not only due to exposure in one allergen but due to exposure to multiple allergens. It is possible that our approach could prove useful towards the detection of multiple exposures to allergens [
Surveillance of contact dermatitis has proven a useful tool since it is essential to unravel time trends in allergic pathologies or in order to discover patterns of lifestyle, environmental stimuli, and occupational hazards [
Recent reports have highlighted both the significance as well as the importance of contact dermatitis studies, which is reinforced by the fact that a European surveillance report is published by collecting data from several European countries and comparing contact dermatitis in a country- and ethnic-dependent manner. In a previous study, we have reported the calculation of an extended MOAHLFA index, a very important parameter in the evaluation of allergic contact dermatitis [
Comparative table of the MOAHLFA index with respect to countries, including the present study (adopted from Uter et al. and Tagka et al. (2015, 2019) [
Country/department | N (test) | M | O | A | H | L | F | A |
---|---|---|---|---|---|---|---|---|
AT/Graz | 1113 | 26.1 | 17 | 20 | 26.2 | 6.8 | 16.7 | 63.9 |
CH total | 4990 | 38.9 | 13.8 | 19 | 26.2 | 7 | 16.3 | 65.8 |
DE total | 7628 | 40.4 | 32 | 24.8 | 40.9 | 7.1 | 11 | 70.3 |
DK/Gentofte/Copenhagen | 2582 | 30.4 | 21.9 | 18.2 | 38.8 | 1.8 | 27.1 | 64.9 |
ES total | 4257 | 31.7 | 12 | 13.8 | 26.4 | 7.8 | 13.7 | 65 |
FI total | 1057 | 37.9 | 44.2 | 30.6 | 59.8 | 3.2 | 4.4 | 56.6 |
IT total | 9267 | 33.4 | 4.6 | 16.6 | 21.6 | 7.3 | 12.3 | 51.2 |
LT/Kaunas | 865 | 19.5 | 13.3 | 11.3 | 25.1 | 11.2 | 22.9 | 63.7 |
NL total | 4385 | 34 | 18.4 | 34.5 | 20.5 | 4.5 | 19.4 | 56.8 |
PL total | 2828 | 28.9 | 22.4 | 13.2 | 29.2 | 3.9 | 15.1 | 56.2 |
SI total | 5224 | 30.7 | — | — | — | — | — | 58.8 |
UK total | 15 532 | 31.9 | 9.7 | 34.6 | 28 | 6.3 | 27.5 | 58.2 |
EL total (Tagka et al. (2019)) | 1978 | 31.29 | 31.55 | 34.98 | 50.20 | 24.31 | 31.65 | 58.29 |
One of the study limitations is the possible first-stage selection bias, which cannot be ruled out. One further difficulty is the comparison of occupational contact sensitization prevalence between countries as well as the inherent differences between the similar departments among different countries. Further on, it would be extremely useful for the understanding of contact sensitization dynamics to be able to perform time-dependent studies, thus, to be able to find patterns of sensitizations and also predict future trends.
In the present study, we have investigated the epidemiological aspects of contact dermatitis by taking into account the occupational profiles of our cohort. This type of analysis will continue by expanding the investigated population, but also we will use improved technological tools for the evaluation and analysis of contact dermatitis. The present cohort under investigation was examined clinically and diagnosis was given by applying classical clinical methods, i.e., the physicians and health professionals’ experience and perception. This procedure will be amended by the use of new computational tools, including artificial intelligence (AI), machine learning, and algorithmic approaches in an attempt to produce a more automated flow for the diagnosis of contact dermatitis.
The present study showed that the prevalence of contact sensitization in all populations, irrespectively of occupational profile, was highest for nickel. Accordingly, the five most prevalent allergens in BlC were nickel sulphate 5%, fragrance mix (i) 8%, Balsam of Peru 25%, potassium dichromate 0.5%, and cobalt chloride 1%. Similarly, the five most prevalent allergens in WhC were nickel sulphate 5%, fragrance mix (i) 8%, Balsam of Peru 25%, thiomersal 0.1%, and cobalt chloride 1%. WhC males were uniquely sensitized to colophony 20% and formaldehyde 2%, and WhC females were uniquely sensitized to CMIT and neomycin sulphate 20%. Our findings indicated that patient stratification based on their occupational profiles could prove useful for their detection of allergen cross-reactions as well as prevention of allergic sensitization due to the occupational profile.
The biological mechanisms behind contact dermatitis are largely unknown. As contact dermatitis is influenced by environmental as well as genetic factors, epidemiological studies are considered of crucial importance towards the understanding of the condition and the establishment of further effective clinical and laboratory tests.
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
The authors declare that there is no conflict of interest regarding the publication of this paper.
The current work was presented in part as a doctoral thesis by the first author, Dr. Anna Tagka [
Patients have been stratified according to their profession, based on the International Standard Classification of Occupations (ISCO). Due to the great variety of professions, we have created a shorter list representing the majority of our population. This final occupational list of the patient cohort is summarized in Supplementary Table 1, which also summarizes the frequencies of the present cohort’s occupational profiles. In Supplementary Table 2, we have used the occupational taxonomy of Supplementary Table 1 and presented the frequencies of the most prevalent allergens in each of these occupations.