Dermatoses associadas ao trabalho em profissionais de saúde de um centro hospitalar português

| Background: Skin diseases account for more than 35% of occupational diseases, affecting 1/1,000 workers annually. Objective: To characterize occupational dermatoses affecting hospital workers and identify possible triggers and susceptibility factors. Methods: Cross-sectional study in which we analyzed information extracted from electronic medical records of workers who performed periodic examinations in the course of one year. Results: About 3.56% of 1,741 included workers had a diagnosis of occupational dermatosis, being mainly women (76.85%). Thirty-four (54.84%) of the affected workers had irritant contact dermatitis, 17 (27.42%) latex allergy, 6 (9.68%) allergic dermatitis, and 5 (8.06%) two concomitant conditions. We found significant difference in prevalence as a function of occupational group (p=0.008), being highest for nursing assistants (5.11%). Prevalence was also higher for employees allocated to surgery departments (8.47%, p=0.001). Main triggers were skin disinfectants, latex, nitrile gloves, and prolonged contact with water (4.84%). Conclusion: The quality of the analyzed data depends on the quality of the analyzed medical records. Most subjects were nursing assistants, which fact hinders the generalization of the results. The prevalence of occupational dermatosis was just 3.56%, which might be explained by previously implemented preventive measures. The employees most frequently affected were those allocated to surgery departments and nursing assistants. Skin disinfectants were the most frequent triggers.

Most cases of contact dermatitis are of the irritant type 1,5 .The involved substance disrupts the stratum corneum, penetrates into the deeper layers of the skin, and damages the keratinocytes 1,10,11 .In turn, skin lesions in allergic contact dermatitis are caused by delayed-type hypersensitivity DTH (type IV) 8,11 .Irritant contact dermatitis not seldom precedes allergic dermatitis [12][13][14] .Contact urticaria to latex is significant among healthcare workers.While the underlying pathophysiological mechanism seems to be different than that of irritant and allergic contact dermatitis, it exhibits high global prevalence among healthcare workers, of 10 to 17% [15][16][17][18][19][20] .
In all the aforementioned cases, occurrence of disease is not only related to the type and intensity of exposure, but also to individual susceptibility.Atopy is the most common predisposing factor, present in up to 20% of cases [21][22][23][24] .
The aim of the present study was to identify and characterize cases of occupational dermatoses among workers in a university hospital center.We further sought to define possible triggers, factors related to individual susceptibility and others potentially related to occurrence of disease.

METHODS
The present cross-sectional study was based on information collected from electronic medical records of employees of a university hospital center.The study population consisted of all employees who performed periodical health examinations at the hospital occupational health department (OHD) in the course of one year (1 May 2017 to 20 April 2018) to a total of 1,741.We reviewed OHD records, which include all clinical information on employees for the past 10 years, considering: sociodemographic data (sex, age), occupational group, hospital department, length in the current job, personal history of atopy, contact dermatitis and latex allergy, dermatitis triggers, relationship between complaints and work (aggravation after exposure, improvement during time off work).We further recorded results of skin allergy tests indicated by dermatologists to workers with symptoms suggestive of contact dermatitis.
As personal history of atopy we considered allergic rhinitis, atopic eczema and allergic asthma.In regard to contact urticaria to latex, we considered all the cases in which this condition was registered in the medical records independently from the date of and presence of signs on the last periodical medical examination.Diagnosis of contact dermatitis was based on clinical findings and skin testing results.For allergic dermatitis, sensitizing agents were investigated my means of DTH skin testing.For irritant contact dermatitis, causal agents were presumably established based on aggravation following contact with definite materials or equipment.For latex allergy, diagnosis was based on its typical clinical presentation in association with specific IgE antibody or a positive DHT skin test.
The present study -which involved reviewing medical records and use of the corresponding data -was approved by the institutional ethics committee, OHD board, and the dermatology department chair.
In statistical analysis we used the Kolmogorov-Smirnov test to investigate the distribution of numerical variables.Association among categorical variables was analyzed with the χ 2 and Fisher's exact tests; mean values for nonparametric numerical variables were compared with the Mann-Whitney test.The significance level was set to 5%.Analysis was performed with software Microsoft Excel and IBM Statistical Package for the Social Sciences (SPSS).
Of the group with occupational dermatosis, 34 workers (54.84%) had a diagnosis of irritant contact dermatitis, 17 (27.42%) of latex allergy, 6 (9.68%) of allergic dermatitis, and 5 (8.06%) of two of these conditions simultaneously -4 cases of latex allergy and irritant contact dermatitis, and one of latex allergy and allergic dermatitis (Figure 1).About 2.18% of the sample exhibited irritant contact dermatitis, 0.40% allergic dermatitis, and 1.26% latex allergy.The proportion of women was higher among the workers with dermatosis compared to those without this condition (82.26% vs. 76.65%), but this difference was not statistically significant (p=0.304).These two groups neither differed as a function of age (p=0.363) or years in the job (median 9.5 vs. 11 years, p=0.791).
The proportion of cases of dermatoses was higher among the employees allocated to surgery departments compared to clinical departments and support services (8.47%, 3.70% and 0.74%, respectively); this difference was statistically significant (p=0.001).
Cases of dermatoses were more frequent among workers with personal history of atopy (4.96% vs. 3.12%), but this difference was not statistically significant (p=0.107).On separate comparisons between personal history of atopy and type of dermatosis (irritant contact dermatitis, allergic dermatitis, latex allergy) we did not find any statistically significant relationship (p=1.000,p=0.389 and p=0.778, respectively) (Table 2).
Putative triggers of irritant contact dermatitis were presumed based on clinical criteria -aggravation of complaints following exposure to definite substances.All these cases test negative for DTH.The agents most commonly involved were skin disinfectants containing alcohol and quaternary ammonium, 76.47% (n=26), nitrile gloves, 17.65% (n=6), and prolonged contact with water, 5.88% (n=2).Alcohol, surface cleaners, surgical masks and a microscope rubber piece were reported by one employee.In regard to allergic dermatitis, thiuram was involved in 4 cases, and skin disinfectants containing quaternary ammonium in 3 -one of them with concomitant latex allergy.

DISCUSSION
Contact dermatitis occurs frequently among healthcare workers, with reported prevalence of 17 to 70% [5][6][7][8]25 . Als the prevalence of latex allergy is quite high for this occupational group (up to 17%) as a function of the ubiquitous use of rubber gloves as part of the personal protection equipment, in addition to other sources of latex exposure [16][17][18][19] .The wide variation in the reported prevalence rates of dermatoses among healthcare workers might be due to methodological differences among studies and the particular working conditions of the analyzed populations.One study performed in 2008 in a Portuguese hospital, involving administration of a questionnaire, found a prevalence of 34.3% of occupational skin disorders among the employees 26 .Differently, in the present study -which data were not collected through questionnaires, but from medical records -the prevalence of dermatoses was just 3.56%.
In addition to the methodological differences, preventive measures implemented at the analyzed hospital might have contributed to reduce the number of cases of occupational dermatosis 14,27 .The hospital OHD participated in the purchase of equipment along the past 10 years, and advised selecting less irritating and sensitizing materials, for instance nitrile or vinyl, thiuram-free gloves.The OHD also contributed to make hand cream available in all the hospital departments, and raised awareness among workers on the relevance of regular use.Employees diagnosed with dermatitis are advised to avoid sensitizing agents and irritants 25,26 , are provided alternative equipment, and are instructed to wear cotton glove liners underneath disposable gloves.These measures might have significantly influenced our results, because we only analyzed clinical information recorded after implementation 21 .
Also the prevalence of latex allergy was lower than that reported in the literature (1.23 vs. 17%) 16 .The reason might be that in the investigated hospital latex gloves are exclusively used during procedures requiring asepsis, and are always powder-free and lower-protein latex gloves 17,27 .A study performed in the same hospital in 2010 -i.e. during the early stage of implementation of the measures described here -the prevalence of latex allergy was 6.6% for nurses 28 , therefore higher than the one we found.
Nevertheless, complaints in 10 cases involved nitrile gloves, including both allergic (to thiuram-containing additives, n=4) and irritant (n=6) contact dermatitis.This finding points to the need for due surveillance, even when the materials used are theoretically safer.
Besides the implemented preventive measures, the low prevalence of dermatosis in the present study might be related to the quality of the medical records.To be sure, we are aware this is one of the limitations of the present study, since the records obviously did not provide information for workers who did not reported complaints during occupational medical examinations for considering them irrelevant or having already been relocated from sites involving exposure (healthy worker effect).
The results relative to susceptibility per occupational group agree with the reports in the literature, since prevalence was higher for nursing assistants, followed by nurses and physicians 23,29 .The possible reason is that these workers are more exposed to irritants and sensitizing agents, such as gloves and skin disinfectants 7 , compared to other occupational groups.Nursing assistants are charged of cleaning and disinfecting surfaces and equipment, in addition to helping nurses in patient care tasks.Prolonged contact with water during the working hours disrupts the stratum corneum of the skin, which by itself increases the susceptibility to irritants and sensitizing agents 1,30 .The same factors explain differences in the prevalence of dermatoses between workers allocated to surgery departments and those in clinical departments and support services.
We found a relationship between occupational dermatosis and personal history of atopy, but it was not statistically significant, neither on separate analysis of the three investigated conditions.While some authors reported possible association between atopic eczema and irritant contact dermatitis, a similar correlation was not yet confirmed for atopy in general 21,23 .Therefore, the lack of association in the present study between personal history of atopy and allergic contact dermatitis or latex allergy agrees with the reports in the literature [21][22][23] .
Since in the present study we analyzed data extracted from medical records, we were not able to establish when exposures to triggers effectively started or ended.For this reason, prospective cohort studies are needed to draw conclusions on the relative risk associated with factors described in the literature as likely to increase the odds of occurrence of dermatoses 12 .
Finally, the fact that nursing technicians represented the majority of workers in the analyzed population -despite a similar distribution of variables sex and age across the entire population -hinders the generalization of the study results.

CONCLUSION
The prevalence of dermatoses for the analyzed sample of 1,741 hospital workers was just 3.56%.Despite limitations inherent to the study design -the quality of records, in particular -preventive measures implemented in the past decade possibly contributed to this outcome.Nevertheless, primary prevention measures should be reinforced as concerns the nursing assistants.Using less sensitizing materials and bolstering the relevance of skin care seem to be essential to reduce the occurrence of dermatosis in this occupational group.