Silver percutaneous absorption after exposure to silver nanoparticles: a comparison study of three human skin graft samples used for clinical applications.

Silver nanoparticles (AgNPs) are increasingly applied to a wide range of materials for biomedical use. These enable a close contact with human skin, thanks to the large release of silver ions that is responsible for a broad spectrum of antimicrobial activity. Silver can permeate the skin; however, there are no data available on silver permeation through skin grafts commonly used in burns recovery. The aim of our study was to evaluate silver penetration using fresh, cryopreserved, and glycerolized human skin grafts after exposure to a suspension of AgNPs in synthetic sweat using a Franz diffusion cell apparatus for 24 h. Silver permeation profiles revealed a significantly higher permeation through glycerolized skin compared with both fresh and cryopreserved skin: 24-h silver flux penetration was 0.2 ng cm(-2) h(-1) (lag time: 8.2 h) for fresh skin, 0.3 ng cm(-2) h(-1) (lag time: 10.9 h) for cryopreserved skin, and 3.8 ng cm(-2) h(-1) (lag time: 6.3 h) for glycerolized skin. Permeation through glycerolized skin is significantly higher compared to both fresh and cryopreserved skin. This result can generate relevant clinical implications for burns treatment with products containing AgNPs.

[Risks of repetitive movements in health personnel]. / Rischi da movimenti ripetitivi nel personale sanitario.

To date, scant attention has been devoted to the occupational risk related to repetitive movements in health personnel. Using three database, PubMed, Scopus, and EMBASE, we found 57 papers on this topic, and on possibly related upper limb symptoms and diseases. In these studies, evaluation of the risk, e.g. using the methods currently applied in industry, are lacking. Although in several studies data on the prevalence of upper limb symptoms and disorders are presented, a comparison of results is difficult as different methods were applied. Furthermore, a comparison with adequate controls is frequently lacking, and/or correlation with the risk was not studied. Despite these limitations, an overall evaluation of the results shows that in health personnel the prevalence of upper limb symptoms/disorders is generally high. Highest prevalences were observed for the neck, shoulder, wrist/hand symptoms and for Carpal Tunnel Syndrome (CTS) in dental personnel, for symptoms to the neck, shoulder and wrist/hand in sonographers, and to the neck, shoulder, elbow, and, especially, wrist/hand in laboratory technicians using manual pipettes. In the nursing personnel highly variable prevalences were observed; this is possibly due to the variability of the tasks performed by this occupational group. Repetitive movements of upper limb are a known risk factor for symptoms to the neck, shoulder, elbow, and wrist/hand, and some disorders, as CTS: the high prevalences observed in health workers may be related to this risk. Nevertheless, other factors such as effort, posture and precision work may play an important role too. As a conclusion, available data are insufficient for an adequate evaluation of the occupational risk related to repetitive movements in health workers.

Penetration of benzene, toluene and xylenes contained in gasolines through human abdominal skin in vitro.

Few studies are available in literature on the risk for humans from skin exposure to gasolines. This work is focused on the in vitro skin penetration of benzene (carcinogenic substance), toluene and xylenes. We examined three commercial gasolines using the Franz diffusion cells and human abdominal full thickness skin. Gasoline composition was determined using a multi-dimensional gas chromatographic (MDGC) technique. Aromatic compounds into the receptor fluid, consisting of saline solution were quantitated by a gas chromatography technique equipped with a flame ionization detector (GC-FID) and coupled with a headspace-solid phase micro extraction system (HS-SPME). Among the three substances, benzene showed the highest average apparent permeability coefficient (K(p)=43.8x10(-5)cmh(-1)) compared to toluene (K(p)=6.48x10(-5)cmh(-1)) and xylenes (K(p)=0.84x10(-5)cmh(-1)). This value could be explained by the lower boiling point and higher water solubility of benzene. Lag times were about 1h for benzene and 2h for toluene and xylenes. Averaged total recoveries in the receptor fluid were 0.43% of dose for benzene, 0.06% for toluene and 0.008% for xylenes. A statistical significative difference (Student's t-test, P<0.05) between the fluxes calculated for the three gasolines are noted only for xylene and for toluene between gasolines #1 (richer in aromatic compounds) and #3. The obtained apparent permeability coefficient are useful for determining the permeability of these aromatics components from gasolines of a different composition. Hands exposure risk, calculated using RfD and RfC as defined by US EPA, is critical for benzene. The risk of skin permeation of gasoline, and, in particular, of benzene, should be better evaluated for those workers who have a large potential for exposure. Adequate personal protective equipment should be used in the high exposure jobs, mainly for hands and forearms.

The European standard series in 9 European countries, 2002/2003 -- first results of the European Surveillance System on Contact Allergies.

Since January 2001, the European Surveillance System on Contact Allergies (ESSCA), supported by European Union funding (contract QLK4-CT-2001-00343), has started to collect patch-test data. This comprises a standardized clinical history and the patch-test results using the European standard series, from 17 centres in 9 European countries listed above. In 2002 and 2003, 10 511 patients' test results have been pooled and analysed. The anamnestic data partly reflect the subspecialties of some centres. The most common allergen was nickel sulfate (17.3%); however, large international variations were observed. The prevalence of contact allergy to Myroxylon pereirae resin (balsam of Peru) (5.8%) is coming close to the frequency found with the fragrance mix (6.4%). Regarding contact allergy to chromium compounds, different frequencies were noted in the 2 centres focused on occupational dermatitis (2.3% in the FIOH versus 7.4% in the Nofer Institute). These most likely reflect the beneficial effect of addition of ferrous sulfate in one, but not the other country. As differences may partly be due to different patch-test reading, standardization may need to be refined further. By providing post-marketing surveillance in the field of contact allergy, ESSCA will meet its objective of increased consumer safety across Europe.

Percutaneous absorption of 5 glycol ethers through human skin in vitro.

Absorption across full thickness human skin was evaluated in vitro for five selected glycol ethers. Skin membranes were settled on static diffusion cells and both neat and 50% water diluted glycol ethers were applied on the donor chamber for 8 h. The amount of glycol ethers permeated into the receptor fluid was measured by gas chromatograph equipped with flame ionization detector (GC-FID). For neat solvents, permeation coefficient Kp ranged from 0.06 to 0.83 cm h(-1) 10(-3) respectively for DEGBEA and EGMEA while for 50% v/v diluted glycol ethers it varied from 0.08 to 1.81 cm h(-1) 10(-3) respectively for DPGME and EGMEA. These experiments show a statistically significant (Student's t-test, P <0.05) increase in permeation coefficients from neat to 50% water diluted glycol ethers and the same trend can be observed in fluxes and lag times. Only DPGME show an opposite behaviour. These results confirm the good ability of these solvents of permeating the skin and show that they could represent a risk for their potential dermal absorption both for workers and for occasional exposures, since the average lag time is 1.57 h.

In vitro predictions of skin absorption of caffeine, testosterone, and benzoic acid: a multi-centre comparison study.

To obtain better insight into the robustness of in vitro percutaneous absorption methodology, the intra- and inter-laboratory variation in this type of study was investigated in 10 European laboratories. To this purpose, the in vitro absorption of three compounds through human skin (9 laboratories) and rat skin (1 laboratory) was determined. The test materials were benzoic acid, caffeine, and testosterone, representing a range of different physico-chemical properties. All laboratories performed their studies according to a detailed protocol in which all experimental details were described and each laboratory performed at least three independent experiments for each test chemical. All laboratories assigned the absorption of benzoic acid through human skin, the highest ranking of the three compounds (overall mean flux of 16.54+/-11.87 microg/cm(2)/h). The absorption of caffeine and testosterone through human skin was similar, having overall mean maximum absorption rates of 2.24+/-1.43 microg/cm(2)/h and 1.63+/-1.94 microg/cm(2)/h, respectively. In 7 out of 9 laboratories, the maximum absorption rates of caffeine were ranked higher than testosterone. No differences were observed between the mean absorption through human skin and the one rat study for benzoic acid and testosterone. For caffeine the maximum absorption rate and the total penetration through rat skin were clearly higher than the mean value for human skin. When evaluating all data, it appeared that no consistent relation existed between the diffusion cell type and the absorption of the test compounds. Skin thickness only slightly influenced the absorption of benzoic acid and caffeine. In contrast, the maximum absorption rate of testosterone was clearly higher in the laboratories using thin, dermatomed skin membranes. Testosterone is the most lipophilic compound and showed also a higher presence in the skin membrane after 24 h than the two other compounds. The results of this study indicate that the in vitro methodology for assessing skin absorption is relatively robust. A major effort was made to standardize the study performance, but, unlike in a formal validation study, not all variables were controlled. The variation observed may be largely attributed to human variability in dermal absorption and the skin source. For the most lipophilic compound, testosterone, skin thickness proved to be a critical variable.

[Incidence of occupational contact dermatitis in the province of Pordenone in the period of 1995-2000]. / Incidenza di dermatite da contatto professionale nella provincia di Pordenone nel periodo 1995-2000.

Occupational contact dermatitis (OCD) ranks first of all occupational diseases in many countries but few are epidemiological data on incidence of this disease. We studied 146 subjects with OCD in Pordenone area in the period 1994-2000. In 90.5% subjects the diagnosis was allergic contact dermatitis and in 9.5% urticaria. Nickel sulfate was the most common sensitizer (14.7%), followed by latex (13.2%) and potassium dichromate (11.6%). Occupational groups at risk were mechanics (51.4%), health service workers (19.9%) and construction workers (7.5%). The incidence rate was 10.8 cases per 10,000 health service workers per year, 8 cases per 10,000 hairdressers and barbers per year, 4.1 cases per 10,000 construction workers per year and 1.9 cases per 10,000 mechanics per year.

[RISKOFDERM: European research project for assessment of occupational skin exposure to chemicals]. / RISKOFDERM: un progetto europeo per la valutazione dell'esposizione per via cutanea a tossici industriali.

OBJECTIVES: RISKOFDERM is a research project whose aim is to develop instruments to assess and manage occupational dermal exposure to chemical substances. METHODS: The research, funded by the European Commission, involves 15 Institutes from 10 member countries; it is a continuation of the Dermal Exposure Network experience and consists of four interrelated parts. The first phase (Qualitative survey) assumed that dermal exposure can be extrapolated from one compound to another when it is task-based: therefore six Dermal Exposure Operation units (DEOu) were defined that lead back to the variety of occupational dermal exposure conditions and an extensive Questionnaire was developed for on-site surveys to perform standard observations in selected working situations (scenarios). RESULTS: The Italian group, participating in the research, obtained a set of observations relating to two "scenarios" in different working sectors: asphalt, ceramic and pottery workers, spectacle decorators and paint production: the aim was to verify the validity of the methodology in assessing the risk of percutaneous absorption, time, frequency and extension of skin exposure. CONCLUSIONS: From the observations made it was shown that the perception of risk was poor; it is necessary to rationalise work organization, and train and inform the employees on the correct use of personal protection devices.

Diaminodiphenylmethane (DDM): frequency of sensitization, clinical relevance and concomitant positive reactions.

Diaminodiphenylmethane (DDM) is an aromatic diamine used in the manufacture of rubber, plastics, diisocyanates, dyes and adhesives. It may cross-react with para-(amino)compounds. Allergic patch test reactions to DDM are relatively frequent, but their relevance is often difficult to detect. We report our experience in 6809 patients (4589 female, 2220 male, mean age 39.9+/-17.8 years) with suspected contact dermatitis patch tested during the period 1997-1999 by the North-East Italy Contact Dermatitis Group (NEICDG). A positive patch test to DDM was detected in 132 (1.9%) patients (88 female, 44 male, mean age 49.5+/-16.2 years). Eczema was mostly localized on the hands. The relevance was detected in 31 patients. A logistic regression analysis showed an association with patient's age (odds ratio 5.4 for age 30-59 years), absence of atopic diseases (odds ratio 3.1) and presence of leg ulcer (odds ratio 5). We found a highly significant correlation (p<0.001) between sensitivity to DDM and to para-phenylenediamine, Disperse Yellow 3, cobalt chloride, fragrance mix, benzocaine, paraben mix and primin. Positive patch test results to DDM were relatively frequent. The difficulty in detecting the relevance of these sensitizations may be related to the surprisingly high frequency of concomitant positive reactions to other allergens.

Percutaneous penetration studies for risk assessment.

During the last few years the general interest in the percutaneous absorption of chemicals has increased. It is generally accepted that there is very few reliable quantitative and qualitative data on dermal exposure to chemicals in the general population and in occupationally exposed workers. In order to predict the systemic risk of dermally absorbed chemicals and to enable agencies to set safety standards, data is needed on the rates of percutaneous penetration of important chemicals. Standardization of in vitro tests and comparison of their results with the in vivo data could produce internationally accepted penetration rates and/or absorption percentages very useful for regulatory toxicology. The work of the Percutaneous Penetration Subgroup of EC Dermal Exposure Network has been focussed on the standardization and validation of in vitro experiments, necessary to obtain internationally accepted penetration rates for regulatory purposes. The members of the Subgroup analyzed the guidelines on percutaneous penetration in vitro studies presented by various organizations and suggested a standardization of in vitro models for percutaneous penetration taking into account their individual experiences, literature data and guidelines already in existence. During the meetings of Percutaneous Penetration Subgroup they presented a number of short papers of up to date information on the key issues. The objective was to focus the existing knowledge and the gaps in the knowledge in the field of percutaneous penetration. This paper is an outcome of the meetings of the Percutaneous Penetration Subgroup and reports the presentations on the key issues identified throughout the 3-year duration of the Dermal Exposure Network (1997-1999).

Sensitization to green coffee beans and work-related allergic symptoms in coffee workers.

BACKGROUND: Occupational respiratory allergy to green coffee beans (GCB) and to castor beans (CB) was studied in 112 workers in a modern coffee manufacturing plant of Trieste (Italy), where the process is completely automatic, the environmental conditions are good and where exposure to CB can be considered absent because since 1970, only new sacks have been used for coffee transportation. METHODS: All subjects were interviewed by a trained doctor using a questionnaire to investigate allergic symptoms and predisposing factors. Sensitization to GCB and to common allergens (pollens, molds, house dust mites) were evaluated by the skin-prick test. The serum of subjects with a positive skin-prick test to CGB or who had symptoms at work was tested for specific IgE (RAST) for GCB and CB. Lung function was evaluated by a Ponigraph spirometer. RESULTS: Sensitization to GCB was found in 25.8% of green coffee workers (31 cases), in 2.7% of roasted coffee workers (37 cases) and in 4.5% of the clerks (44 cases), p < 0.01. The evaluation of IgE specific for CB gave positive results only in 3 of 10 subjects sensitized to GCB. A total of 20% of GCB workers (6 cases) complained of work-related respiratory symptoms (asthma and/or rhinitis) compared with only one subject in the roasted coffee group and one in the control group (p < 0.01). Asthma was reported by 2/31 of the green coffee workers and by 1/44 of roasted coffee workers. CONCLUSIONS: There was a significant correlation between sensitization to GCB and work related symptoms (p < 0.01), common allergic symptoms (p < 0.05) and atopy by prick test (< 0.01). These results point to the need to evaluate atopic status in workers and identify the most susceptible subjects, with the aim of informing them of their at-risk status and monitoring their progress. This makes it possible to diagnose sooner those symptoms possibly indicative of a work-related disease, because even in presence of good environmental conditions and even when symptoms are mild, it is almost always the atopic subjects who are affected.

Liver function alterations in synthetic leather workers exposed to dimethylformamide.

A cross-sectional study of the prevalence of chronic liver function alterations was performed in 75 workers employed in a synthetic leather factory, exposed to dimethylformamide (DMF) air concentrations below threshold limit values (30 mg/m3). Biological monitoring among workers revealed acceptable urine levels of monomethylformamide (NMF) on average, but the very wide range indicated that occasional overexposure was possible. The worker survey showed a high percentage of disulfiram-like symptoms (50%) and liver function abnormalities (22.7%), compared with a demographically similar group of unexposed workers. Covariance analysis (ANCOVA) revealed that enzyme levels were significantly higher in exposed workers than in controls after data were corrected for age, alcohol consumption, body mass index, and cholesterol levels. The authors conclude that DMF can cause liver diseases even if air TLVs are respected, because accidental contact with liquid DMF can significantly increase DMF uptake. In this situation, air monitoring is no longer sufficient to evaluate worker exposure.

[Respiratory symptoms and occupational sensitization in a group of trainee bakers: results of a 6-month follow up]. / Sintomi respiratori e sensibilizzazioni professionali in un gruppo di allievi panificatori: risultati di un follow-up a 6 mesi.

We investigated the prevalence of atopy by 4 different criteria (personal and family atopy, atopy by prick test and by serum IgE levels), and sensitization to wheat flour and alpha amylase in a group of trainee bakers and in a group of trainee graphic artists as controls (baseline check-up). The follow-up was performed 6 months later only among trainee bakers (90 cases), based on an updating questionnaire and on repeated skin prick test with wheat flour and alpha amylase extracts. Trainee bakers and controls were similar with respect to age, number of smokers, atopy evaluated by 4 different criteria, and detection of serum IgE (RAST) and IgG specific to wheat flour. Positive skin prick test to wheat flour (4%) and alpha amylase (1%) were found only among trainee bakers. At the baseline control 4 students (4.4%) complained of respiratory symptoms when working with wheat flour (WRS). At the six month follow up 6.6% of the trainee bakers complained of WRS: 3.3% had persistent symptoms, 3.3% were new cases and 1.1% had become asymptomatic. Five cases (5.5%) were skin positive to wheat flour or alpha amylase, but only one was unchanged, while 4.4% were new cases and 3.3% turned negative. None of these changes was statistically significant (McNemar test). The trainee bakers complaining of WRS at the baseline or at follow-up (7 cases, when compared with the non-symptomatics, showed a higher prevalence of personal atopy and skin sensitization to occupational allergens; there were no differences, however, with regard to atopy by prick test, IgE levels or the presence of wheat specific IgE and IgG. The trainee bakers skin positive to the occupational allergens (8 cases) showed prevalences of personal atopy and atopy by prick test significantly higher than trainee bakers skin negative to wheat flour or alpha amylase (p < or = 0.01). Evaluating wheat flour specific IgE and IgG in the serum of trainee bakers and controls provided us with more information about the specificity of such tests and suggests caution in attributing the presence of these immunoglobulins in the serum to specific occupational exposure or to specific occupational sensitization. A six-month follow up is likely to be too short an interval to observe significant changes in work-related symptoms and in skin sensitization to occupational allergens. The results, however, emphasize the important role of personal atopy as a predisposing factor in the development of occupational disease among trainee bakers.

[Allergic sensitization and latex-associated symptoms in a group of health workers]. / Sensibilizzazione allergica e sintomi associati al lattice in un gruppo di lavoratori della sanità.

The presence of symptoms connected with the use of latex rubber gloves and sensitization to this allergen was studied in a group of 660 hospital workers who regularly used gloves as a means of protection. Symptoms connected with the use of gloves were reported by 153 subjects (23.2%) and were significantly associated with female subjects length of use and type of medical care. The majority of cases reported irritative symptoms (13.2%) whereas contact dermatitis and rash were reported by 3.6% and 5.5% of cases respectively. Systemic reactions (asthma and/or rhinitis) were reported by 5 subjects. Prick tests for latex were positive in 23 cases (3.5%), 15 of which were symptomatic. Positive skin reaction to latex was significantly associated with family atopy, personal case history and prick test. It is concluded that the presence of symptoms and sensitization to latex requires the implementation of preventive measures in order to reduce the risk of sensitization to a minimum, in addition to removal from exposure of those subjects who are already symptomatic or at risk.

Pre-employment screening among trainee bakers.

OBJECTIVES: To assess the prevalence of atopy in a vocational school so as to evaluate the feasibility of pre-employment screening. METHODS: The prevalence of atopy by family diathesis, prick tests, immunoglobulin E (IgE) concentrations, and personal history of allergic respiratory diseases was investigated in 144 trainee bakers and 81 students on a graphic artists course (mean age 15.4 years). Skin sensitisation to wheat, rye, and barley flours, to alpha amylase, and to storage mites was also evaluated. RESULTS: Personal allergic symptoms were reported by 13.2% of the bakers and 14.7% of the graphic artists and there was a significant association between symptoms and atopy by prick tests (odds ratio (OR) 17.2; 95% confidence interval (95% CI) 5.27-56.4) and by family history (OR 3.11; 95% CI 1.02-9.53). When bakers were grouped according to the presence of allergic symptoms and results of immunological tests, 6.9% had asthma, 6.3% had rhinoconjunctivitis, and a high percentage (28.5%) were without symptoms but scored positive on prick tests or family symptoms. Skin sensitisation to storage mites had similar prevalences (16%) in the two groups of trainees and occurred nearly always in atopic people. Positive skin tests to wheat flour (3.5%), rye (0.7%), and alpha amylase (0.7%) were specific to bakers. CONCLUSIONS: Pre-employment screening is a useful source of medical information and allows for counseling. The presence of asthma, or of another allergic disease in a severe form, is suggested as a criterion for excluding students of a vocational school from training as bakers. Student bakers without allergic symptoms but atopic by other criteria should be informed about their risks of developing occupational asthma, and periodic check ups must be recommended. Screening studies in vocational school provide a better understanding of specificity of skin sensitisation to occupational allergens.

Allergic airway disease in Italian bakers and pastry makers.

A survey was carried out on respiratory symptoms and skin prick test response to common allergens (atopy), storage mites, and occupational allergens among 226 bakers and pastry makers from 105 small businesses in northern Italy. Atopy was present in 54 workers (23.4%); 40 workers (17.7%) were skin positive to at least one storage mite, 27 (11.9%) to wheat flour and 17 (7.5%) to alpha-amylase. Work related asthma was reported by 11 (4.9%) workers and rhinoconjunctivitis by 31 (17.7%); 22 workers (10.2%) complained of chronic bronchitis. The distribution of skin prick test results among bakers and among 119 white collar workers did not indicate (by logistic analysis) an increased risk for bakers to skin sensitisation to common allergens, storage mite, or to a group of five flours. Sensitisation to wheat flour, on the other hand, was present only among exposed workers. Skin sensitisation to occupational allergens was significantly associated with atopy (p < 0.001), smoking habit (p = 0.015), and work seniority (p = 0.027). The risk of work related symptoms was associated with sensitisation to wheat or alpha-amylase, and with atopy, but not with sensitisation to storage mites, work seniority, or smoking habit. The results of the study indicate that there is still a significant risk of allergic respiratory disease among Italian bakers. Not only wheat allergens, but also alpha-amylase must be considered as causative agents, although sensitisation to storage mites is not important in the occupational allergic response. Atopy must be regarded as an important predisposing factor for skin sensitisation to occupational allergens and for the onset of symptoms at work. The data confirm that for effective prevention, greater care should be taken not only in limiting environmental exposure, but also in identifying susceptible people.

Musculoskeletal disorders in hospital nurses: a comparison between two hospitals.

Nursing staff members of a urban general hospital (GH) and a small oncological department (OD) were surveyed to determine the prevalence of occupational related musculoskeletal disorders (MSDs), the specific disabilities, accidents at work, and working time lost. All subjects had a medical examination to evaluate osteoarthicular disease and selected cases were invited to X-ray examinations. The purpose of this study was to compare MSDs in the two groups of nurses working in two hospitals with different work organization in the same geographical area, Pordenone in Italy. In the previous year 48% GH and 33% OD nurses reported back pain due to work, 29.4 and 16.1% respectively have had X-ray or orthopaedic examinations, 19.2% and 9.1% had been away from work because of back pain. All these differences are statistically significant. The analysis of musculoskeletal pain sites and working tasks in the two hospital workers shows no differences in distribution. Great difference exists when analysing the numbers of patients assisted by a nurse: 0.57 and 1.27 nurse/patients respectively in GH and OD. Our data indicate a high overall frequency of occupational back pain, similar to other studies in Europe. The comparison between the two hospitals suggests factors associated with the disorder: work tasks and particularly nurses/patients ratio are more important factors than age and length of exposure. Different work distribution, shift organization, a better ratio between nurses and patients, an improvement of equipment provision, and specific nurse-training with application of ergonomic methods could improve work efficiency radically and decrease injury rates.

[Alpha-amylase as an occupational allergen in baking industry employees]. / L'alfa amilasi come allergene professionale negli addetti alla panificazione.

In a group of 226 bakers and pastry makers and in 88 students of a training school for bakers, we evaluated skin sensitization to the common allergens, wheat and alpha amylase. Skin prick tests were positive to the enzyme in 17 exposed subjects (7.5%) and in one student with previous occupational exposure as a baker; 27 exposed subjects (11.9%) and 2 students were sensitized to wheat. Among the 42 exposed workers who complained of work-related symptoms, 12 (28.6%) cases were skin positive to amylase and 17 (42.9%) to wheat. Among the 17 workers who were positive to amylase, 16 were also sensitized to wheat and/or common allergens, 12 complained of symptoms at work but since in many cases there was a positive response to wheat, too, it is impossible to speculate on the role of each allergen in inducing symptoms. One case, with work-related rhinoconjunctivitis, had skin sensitization only to alpha amylase but no specific IgE in the serum. These findings confirm that bakers are at risk of sensitization not only to wheat allergen but also to amylase from Aspergillus oryzae. The enzyme should be included in the list of substances to be tested among bakers in whom an occupational allergy is suspected, but particular care should be taken in evaluating the cutaneous response, especially if compared to wheat wheals. Further investigations are also needed to identify the source of risk and to better define the characteristics of the enzyme and the relationship between skin reaction to amylase, sensitization to wheat and atopy.(ABSTRACT TRUNCATED AT 250 WORDS)