Prospective study of laboratory-animal allergy: factors predisposing to sensitization and development of allergic symptoms

In a prospective study of laboratory technicians, selected indicators of allergy and atopy were studied in an attempt to determine predictors of laboratory-animal allergy (LAA). Laboratory technicians underwent spirometry, methacholine provocation tests, and blood sampling, and responded to a questionnaire during training and after 2 years' work. Among 38 laboratory-animal-exposed subjects, total IgE before exposure gave the best correlation ( P < 0.01; Mann-Whitney U-test) to reported symptoms caused by laboratory animals ( n = 8) at follow-up. The prevalence of atopy and allergic symptoms had increased in exposed technicians at follow-up, but this was also found among unexposed matched referents ( n = 36 pairs). One subject in the exposed group reported asthma before exposure, compared with seven at follow-up ( P < 0.05; Fisher's exact test). However, the prevalence of asthma had increased from two to six (not significant) also among unexposed technicians. There were no significant differences between the groups in any measured variable at follow-up. Among 43 subjects who later worked with laboratory animals, 21%, had a positive skin prick test for common allergens, as compared with 37% among 112 without animal exposure P = 0.06; x² test), suggesting selection for laboratory animal work.     

Characterization of occupational sensitization by multiallergen immunoblotting in workers exposed to laboratory animals

BackgroundStudies have estimated that 10% to 23% of workers exposed to laboratory animals report symptoms of laboratory animal allergy.ObjectivesTo determine the level of occupational sensitization in workers exposed to laboratory animals and to develop a diagnosis system based on a multiallergen IgE immunoblot.MethodsA total of 75 workers exposed to laboratory animals were initially studied with skin prick tests performed with animal epithelia extracts. The workers with suspected occupational disease and positive skin prick test results were further studied with the ImmunoCAP system to determine specific IgE levels to urine and epithelia allergens and with multiallergen IgE immunoblotting to detect specific IgE levels to epithelia allergens and bovine serum albumin.ResultsTwenty of the 75 workers were studied with ImmunoCAP and multiallergen IgE immunoblotting. Nine were polysensitized and 3 were sensitized to only one animal. The results obtained by ImmunoCAP and multiallergen IgE immunoblotting were concordant except for in 3 workers, who had low or negative values of specific IgE determined by ImmunoCAP but positive allergen detections by immunoblotting. On the basis of the results of the study and the clinical symptoms related by workers, 16% were diagnosed as having occupational allergy.ConclusionsMultiallergen immunoblotting by means of a unique test offers a graphic representation of sensitization to the different animals to which workers are exposed, providing additional information on the clinical symptoms caused by the involved allergens. The results presented suggest that this system can improve the diagnosis of laboratory animal allergy by obtaining a sensitization profile for each exposed worker.     

Working with male rodents may increase risk of allergy to laboratory animals

BACKGROUND: Our aim was to study the risk of laboratory animal allergy (LAA) among research staff working in laboratories separate from the animal confinement area. The roles of atopy and exposure intensity in LAA were studied with special regard to exposure to male rodents, who excrete higher levels of urinary allergens than female rodents. METHODS: Eighty rodent-exposed subjects gave blood samples for the analysis of total IgE, Phadiatop, and specific IgE against rat (RUA) and mouse urinary allergens (MUA), and answered questionnaires. Air samples were collected for RUA and MUA aeroallergen measurement in both laboratories and animal confinement facilities. RESULTS: Twenty percent of the subjects had IgE >0.35 kU/l to RUA and/or MUA, and 32% had experienced animal work-related symptoms, although 90% of aeroallergen samples from the research department laboratories were below the detection limit (<0.26 ng RUA per m(3) and <0.8 ng MUA per m(3)). Atopy (positive Phadiatop), total IgE >100 kU/l, other allergies (especially to other animals), or more than 4 years of exposure significantly increased laboratory animal sensitization and symptoms. Working with mainly male rodents gave odds ratios (95% CI) of 3.8 (0.97-15) for sensitization and 4.4 (1.4-14) for symptoms. Subjects with both exposure to mainly male rodents and atopy or elevated total IgE had a 10-fold higher frequency of sensitization than exposed subjects with neither risk factor. CONCLUSION: A majority of subjects with a combination of exposure to mainly male rodents and atopy or elevated total IgE developed sensitization to and symptoms from laboratory animals. Current low exposure seems to maintain the presence of specific IgE. Further measures must be undertaken to provide a safe workplace for laboratory animal workers.     

Influence of natural exposure to pollens and domestic animals on airway responsiveness and inflammation in sensitized non-asthmatic subjects

BACKGROUND: Atopy may be a risk factor in the development of asthma. Indoor allergens are considered to be more potent asthma inducers than outdoor ones such as pollens. Lower airway inflammation may be present in non-asthmatic subjects during natural exposure to relevant allergens and may eventually lead to the development of asthma. AIMS: To document seasonal variation in lower airway responsiveness and inflammation in sensitized non-asthmatic subjects, during natural exposure to allergens, and to determine whether it is more marked in those exposed to animals to which they are sensitized. METHODS: Twenty-two atopic subjects were seen during and out of the pollen season. All (but the controls) were sensitized to domestic animals, and to trees, grasses or ragweed. Eleven were not exposed to animals at home and 8 were exposed. They were compared with 3 normal controls. A respiratory questionnaire was administered, allergy skin prick tests, spirometry, methacholine challenge, blood and induced sputum with differential cell counts were obtained during the pollen season for all subjects. These tests were repeated out of the pollen season. RESULTS: Throughout the study, none of the subjects had asthma symptoms. Mean PC(20) was significantly lower in subjects exposed to animals compared with unexposed subjects or controls, both during and out of the pollen season. In season, subjects exposed to animals had significantly higher sputum eosinophil numbers than unexposed or normal control subjects. CONCLUSIONS: Non-asthmatic atopic subjects show variable degrees of airway responsiveness and inflammation. However, subjects exposed to animals show higher airway eosinophilia, which may suggest they are at increased risk of developing airway hyperresponsiveness and asthma.     

Frequency of allergic rhinitis to laboratory animals in university employees as confirmed by chamber challenges

BACKGROUND: Occupational risk for laboratory animal allergy (LAA) is well known, but prevention is often insufficient and new cases keep appearing. METHODS: A questionnaire on work-related symptoms was sent to all laboratory animal workers in Kuopio University. Subjects with rhinitis were invited to an examination for LAA, which consisted of an otorhinolaryngological examination and skin prick testing (SPT) with 16 common environmental allergens and two to five relevant laboratory animals. In cases of occupational sensitization, a challenge test was performed. RESULTS: The questionnaire was completed by 156 of 245 (64%) subjects. Rhinitis was reported by 65 of the respondents (42%) of whom 47 were examined for LAA. The duration of exposure before the onset of rhinitis varied from 1 month to 18 years. Twenty-seven persons (57%) had a history of some previous atopic symptoms. Forty subjects (85%) showed positive reactions in SPT, 24 (51%) for laboratory animals. Fifteen of the 26 animal challenge tests performed were positive, confirming the diagnosis of occupational allergic rhinitis in three subjects, occupational dermatitis in five and both diseases in seven subjects. The frequency of occupational allergic rhinitis among all participants was 10 of 156 (6%). CONCLUSIONS: Atopic constitution and work-related sensitization were common in rhinitic laboratory animal workers. Occupational allergic disease was diagnosed in nearly every third case.     

Only few workers exposed to wood dust are detected with specific IgE against pine wood

BACKGROUND: Our aim was to investigate the frequency of pine allergy in woodworkers with respiratory symptoms and to identify high molecular weight allergens in pine wood extracts. METHODS: In a cross-sectional study we examined work-related respiratory symptoms in 2033 furniture workers and 474 controls by questionnaires. Clinical examination was performed in 365 wood dust exposed and 116 nonexposed subjects. Blood samples were collected for measuring pine-specific immunoglobulin (Ig)E by an immunoassay and Western blots. RESULTS: Eleven exposed and three nonexposed subjects had pine-specific IgE. In the group with clinically defined asthma eight persons (5.4%) had pine-specific IgE compared with six persons (1.8%) in the group without asthma (P < 0.05). In the groups with and without respiratory symptoms, 13 (3.8%) and one (0.7%) subject, respectively, had pine-specific IgE (P = 0.06). Western blots demonstrated pine-specific IgE to components in the molecular range of 14 - 100 kD in eight samples (all wood dust exposed). Five samples had pine-specific IgE against components in a 43 - 59 kD zone and against two bands at 27 and 29 kD that are candidates for major allergens. CONCLUSION: Some workers in the Danish furniture industry are specific IgE sensitized against pine wood dust. Pine-specific IgE probably explains a minor part of the respiratory symptoms in workers exposed to pine wood dust.     

HLA associations with occupational sensitization to rat lipocalin allergens: a model for other animal allergies?

BACKGROUND: Laboratory animal allergy is a common occupational health problem affecting between 11% and 44% of exposed researchers. Allergy to rats and mice is most common, probably because these are the animals most frequently used. OBJECTIVE: We hypothesized that HLA class II molecules, involved in the presentation of allergen to the T cell and likely candidates for controlling the immune response, might be associated with sensitization to rat urinary proteins among laboratory animal handlers. METHODS: We undertook a cross-sectional study of 741 employees at 6 pharmaceutical sites across the United Kingdom who had contact at work with laboratory rats. In all, 109 cases with specific sensitization to rat proteins and 397 referents were HLA-typed for DRB1 and DQB1 loci. Amino acid analyses of significantly associated HLA molecules were carried out. RESULTS: HLA-DR7 was associated with sensitization (odds ratio [OR], 1.82; CI, 1.12-2.97), respiratory symptoms at work (OR, 2.96; CI, 1.64-5.37) and, most strongly, sensitization with symptoms (OR, 3.81; CI, 1.90-7.65). HLA-DR3 was protective against sensitization (OR, 0.55; CI, 0.31-0.97). Amino acid analyses of these 2 molecules indicated a biologically plausible explanation for the associations. CONCLUSION: HLA phenotype is an important determinant of individual susceptibility to sensitization and asthma among laboratory animal workers. Similar mechanisms might apply in other animal allergies.     

Exposure-response relationships for work-related sensitization in workers exposed to rat urinary allergens: results from a pooled study

BACKGROUND: Recent studies in a few industries have shown that the likelihood of IgE-mediated sensitization increases with increasing exposure. The shape of the exposure-response relationships and modification by age, sex, and smoking habit has hardly been studied. OBJECTIVE: The purpose of this study was to determine exposure sensitization relationships for rat sensitization and to evaluate the influence of atopy, smoking habits, and sex. METHODS: Data from 3 cross-sectional studies in The Netherlands, the United Kingdom, and Sweden were used and involved 1062 animal laboratory workers. Selection criteria were harmonized, and this resulted in a study population of 650 animal laboratory workers (60.6% female) with less than 4 years of exposure. Air allergen levels were assessed previously and converted on the basis of an interlaboratory allergen analysis comparison. Available sera were analyzed for the presence of specific antibodies against common allergens (house dust mite, cat, dog, and grass and birch pollen) and work-related allergens (rat and mouse urinary proteins). Questionnaire items on work-related respiratory symptoms, hours worked with rats per week, job performed, smoking habits, and sex were used in this analysis RESULTS: The prevalence of work-related sensitization to rat urinary allergens (IgE >0.7 KU/L) was 9.7 % (n = 63). Thirty-six of the sensitized workers had work-related symptoms (asthma or rhinitis). Two hundred forty-eight workers (38.2%) were atopic (defined as specific IgE to 1 of the common allergens). The sensitization rate increased with increasing air allergen exposure. Atopic workers exposed to low levels of allergen had a more than 3-fold increased sensitization risk compared with nonexposed atopic workers. For atopic subjects, the risk increased little with increasing exposure, whereas for nonatopic subjects, a steadily increasing risk was observed. Smoking and sex did not modify the sensitization risk. CONCLUSION: Rat urinary allergen-sensitization risk increased with increasing exposure intensity. Workers who were atopic had a clearly elevated sensitization risk at low allergen exposure levels.     

Prevalence and diagnosis of laboratory animal allergy

A survey of the prevalence of laboratory animal allergy to rats, mice, guinea pigs and rabbits among sixty-nine animal workers and 308 other subjects on a pharmaceutical research site revealed a 22% prevalence of laboratory animal allergy among the animal workers. The overall prevalence of atopy was 67% in persons with allergy to laboratory animals. This was significantly greater than the 31% prevalence in other animal workers. Skin-prick tests and specific IgG and IgE assays to urinary protein extracts strongly correlated with the occurrence of laboratory-animal allergy and would appear to have diagnostic value. However, a number of clinically diagnosed laboratory-ani-mal-allergy subjects gave no evidence of immunological response to the urinary allergens and wider diagnoses may have to be applied in these cases.     

Prevalence of occupational allergy due to live fish bait

BACKGROUND: Larvae of insects and worms, used as live fish bait (LFB), are a common source of allergy in anglers and occupationally exposed workers, but the prevalence and predictors have not yet been investigated. OBJECTIVE: This study assessed the prevalence and associated factors of occupational allergy in workers exposed to LFB. METHODS: We assessed the prevalence of sensitization to LFB and work-related symptoms (WRS) in 76 workers occupationally exposed to it. All workers completed a case history questionnaire and underwent skin prick tests (SPT) for common aeroallergens and bluebottle (Calliphora vomitoria), bee moth (Galleria mellonella), mealworm (Tenebrio molitor), and gusano rojo (Cilecomadia moorei). Specific IgE were tested in 64 subjects. Two-thirds of the workers had a high level of LFB exposure. RESULTS: Sensitization to LFB was found in 24 workers (31.6%). Seven subjects (9.2%) reported WRS (asthma in 3, rhinoconjunctivitis in 5, and contact urticaria in 1), and 5 were positive for SPT and serum IgE to one or more LFB extracts. One was also exposed to LFB while fishing. Sensitization to LFB extracts and WRS were strongly associated (Odds Ratio = 6.6, P < 0.05). The 7 subjects with WRS had been exposed longer than asymptomatic subjects with positive skin tests to LFB (P < 0.05). No differences in sex, age, smoking habit, duration or level of exposure, and atopy were detected in symptomatic or in sensitized subjects, compared with normal workers. CONCLUSION: Sensitization to LFB and WRS are relatively frequent in occupationally exposed workers. No associated factors of occupational allergy to LFB could be detected.     

Skin tests and blood leukocyte histamine release of patients with allergies to laboratory animals

Skin tests and in vitro histamine-release reactions were used to evaluate 130 patients observed in an employee allergy clinic at a biomedical research facility. The allergens used included extracts from pollens (ragweed, grasses, trees, weeds), molds, mixed feathers, house dust, cat, dog, mouse, rat, rabbit, guinea pig, and hamster. Of all patients, 66% complained of allergic symptoms on laboratory animal exposure, although only 52% worked directly with animals. Among patients with symptoms, 91% were positive by skin test to at least one laboratory animal, and 46% had asthma. The median length of exposure to laboratory animals before onset of symptoms was 2.8 yr with 60% of the patients developing their symptoms within 3 yr. Among patients who had allergic symptoms before exposure to laboratory animals, 79% were skin test positive to laboratory animals when they were evaluated in this study. There was a close association found between the skin test and histamine-release results with the laboratory animal allergens: 91% of the 4+ skin reactors had leukocytes positive for histamine release versus 5% of the leukocyte donors with less than 1+ skin reactions. A close relationship in positive reactions to different laboratory animal allergens was also found. For example, individuals positive to mouse were positive also to rat (95%), rabbit (79%), guinea pig (83%), and hamster (88%). Patients who reacted to laboratory animals also reacted to some extent to house dust and cat and dog allergens, and about one half of the animal-allergic individuals reacted to pollens. Although nonpollen-allergic individuals can develop sensitivity to laboratory animals, the group at higher risk are allergic individuals, especially those sensitive to house dust, cats, or dogs.     

New insights into laboratory animal exposures and allergic responses

PURPOSE OF REVIEW: To update the epidemiology of laboratory animal allergy, identify new exposures in the laboratory animal workplace, discuss complexities in the exposure-response relationship, and review the immunology of symptomatic and allergic responses. RECENT FINDINGS: Laboratory animal allergy remains a common occupational hazard of research scientists, technicians and animal handlers. The epidemiology is typical of a stable workforce: incidence is low, although prevalence is high. Risk factors of atopy, current exposures, and sensitization to cats or dogs incompletely predict disease. Exposures include a complex, potent mixture of allergens, biological adjuvants such as endotoxin and irritants. The dose-response relationship between laboratory animal exposure, sensitization and symptoms is hard to define: cross-sectional studies identify most sensitized workers in moderate laboratory animal exposure, not in the highest exposure. Exposure assessments based on workday averages underestimate exposure peaks that may be significant for symptoms and disease. Although we have assumed that workers without symptoms are not sensitized to laboratory animal allergens, recent data demonstrate that many asymptomatic workers do make laboratory animal-specific immune responses that may be necessary to prevent symptomatic disease. SUMMARY: Understanding laboratory animal exposures and disease must include exposures other than allergen, and responses other than allergic disease.     

Immunoglobulin G4 antibodies to rat urinary allergens, sensitization and symptomatic allergy in laboratory animal workers

BACKGROUND AND OBJECTIVES: We have previously reported that high rat urinary allergen (RUA) exposure was not associated with increased risk of rat allergy in long-term-exposed laboratory animal (LA) workers. We aimed to assess whether strong allergen-specific IgG4 responses could explain the absence of a dose response in these subjects. We investigated whether IgG4 was associated with allergen exposure and prevalence of sensitization or respiratory symptoms to rats. The longitudinal relation between IgG4 and rat allergy was studied using data obtained during 2 years of follow-up. METHODS: Five hundred and twenty-nine LA workers answered a questionnaire on respiratory symptoms and occupational history and participated in skin prick testing. Blood samples were analysed for specific IgG4 and IgE to RUA. Exposure to RUA was estimated based on personal air samples. The relation between IgG4 and newly occurring sensitization or rat allergy was studied in workers who were not sensitized or did not report respiratory symptoms to rats. RESULTS: IgG4 titres were higher in atopic than in non-atopic subjects, and increased with higher allergen exposure. Titres were highest in subjects who were sensitized and reported respiratory symptoms to rats when compared with those who were not (geometric mean [geometric standard deviation] = 202 [5.7] vs. 8.4 [18.3] AU). The association between IgG4 and sensitization or symptomatic rat allergy was independent of estimated allergen exposure. IgG4 was a strong predictor of newly occurring sensitization and symptomatic rat allergy during follow-up in atopic and rat-sensitized subjects. CONCLUSION: High exposure to RUA is associated with a strong allergen-specific IgG4 antibody response. High anti-RUA IgG4 is a strong predictor of prevalent and incident sensitization and symptomatic rat allergy in atopic and rat-sensitized subjects. IgG4 can therefore not explain the absence of a dose response between allergen exposure and allergy in long-term-exposed workers. We consider anti-RUA IgG4 to be a marker that combines aspects of exposure and susceptibility.     

Asthma induced by inhalation of flour in adults with food allergy to wheat

Background Wheat is one of the major food allergens and it is also an inhalant allergen in workers exposed to flour dusts. Food allergy to wheat in adulthood seems to be rare and has never been reported to be associated with asthma induced by flour inhalation.
Objective The study aimed at detecting adults with food allergy to wheat and screening them for the presence of specific bronchial reactivity to inhaled wheat proteins.
Methods Adults with a history of adverse reactions to ingestion of wheat underwent skin prick test with commercial wheat extract and were assessed for the presence of specific wheat IgE in the sera. Food sensitivity to wheat was confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Specific bronchial reactivity was investigated through a specific bronchial challenge with wheat proteins.
Results In nine patients with evidence of specific IgE response to wheat, a diagnosis of food allergy was made by DBPCFC. Only two subjects had asthma as disease induced by ingestion of wheat. Seven subjects reported a history of respiratory symptoms when exposed to flour dusts. A significant reduction of forced expiratory volume in 1 s (FEV₁) was detected in these seven patients when a specific bronchial challenge with flour proteins was performed. Only three out of seven subjects with asthma induced by flour could be considered occupationally exposed to flour dusts.
Conclusion For the first time, it has been shown that specific bronchial reactivity to wheat proteins can be detected in patients with different disorders associated with food allergy to wheat. The presence of asthma induced by inhaled flour is not strictly related to occupational exposure and it may also occur in subjects not displaying asthma among symptoms induced by wheat ingestion.     

Occupational allergy in laboratory workers caused by the African migratory grasshopper Locusta migratoria

BACKGROUND: Recent reports of fatal asthma cases associated with swarms of locusts affecting African countries have highlighted the importance of this insect in causing asthma morbidity and mortality. However, only limited information is available about the allergic health outcomes such as asthma and its determinants in exposed individuals. In this study, workers exposed to the African migratory locust Locusta migratoria were evaluated for allergic health outcomes as well as the nature of the offending allergens. METHODS: Ten scientists and technicians exposed to locusts in a laboratory were investigated for locust-related allergy using questionnaires and immunological tests. The presence of allergy was determined by quantification of specific IgE and IgG to L. migratoria using the UniCAP system and via skin-prick testing (SPT). The allergens were characterized by Western blot and ImmunoCAP inhibition assays. RESULTS: Six of the 10 workers experienced symptoms ranging from urticaria and rhinoconjuctivitis to asthma. Seven individuals demonstrated sensitivity on SPT and five had specific IgE antibodies to L. migratoria. Significant cross-reactivity was demonstrated for allergens in the locust faeces, body and wings but not to cockroach allergens. Novel allergens with molecular weights of approximately 70 kDa were identified in locust wings, which are distinctly different from other known allergen sources from locusts. CONCLUSION: Exposure to L. migratoria allergens is a potential sensitizer in exposed individuals. Raised levels of locust-specific IgE can be readily quantified. The wings of this insect species have been identified as a novel allergen source.     

Occupational asthma and rhinitis related to laboratory rats: serum IgG and IgE antibodies to the rat urinary allergen

Allergic reactions to rat urinary proteins are an important cause of occupational asthma and rhinitis among laboratory workers. We have measured IgG and IgE antibodies to a purified rat urinary allergen in sera from 179 laboratory workers of whom 30 reported symptoms on exposure to rats. There was a very good correlation between IgE antibodies and positive skin tests. In addition, there was a close correlation between reported asthmatic reactions and serum IgE antibody to rat allergen: IgE ab was present in 12/18 of workers with asthmatic reactions but in only 2/135 of workers without symptoms (p less than 0.001). Serum IgG antibodies to rat allergen were present in all sera with IgE antibody but were also present in 30% of asymptomatic individuals. The incidence and quantity of IgG antibody correlated with the degree of exposure to animals (i.e., hours per day) but not with the length of exposure in years. Our results on rat allergy confirm that there is an increased incidence of asthma among individuals who were atopic as judged by positive skin tests to other allergens. However, this relationship did not apply to individuals with rhinitis alone, and excluding atopic individuals from employment would have been a very inefficient method of reducing asthma or rhinitis in this group. Our results confirm that IgE antibody responses to rat urinary allergen are an important cause of occupational disease. The results for IgG antibody suggest that their prevalence represents a marker for the degree of exposure to rat proteins.     

Occupational asthma and allergy in the detergent industry: new developments

This review highlights the latest developments in the control of enzyme-induced occupational asthma and allergy (rhinitis and conjunctivitis) in the detergent industry. The industry has developed guidelines for the safe handling of enzymes in order to reduce the risk of occupational allergy and asthma. Those manufacturing facilities that follow all of the guidelines enjoy very low or no cases of asthma and allergy among workers exposed to enzymes. The key to the success of the management of enzyme-induced allergy and asthma is prospective surveillance for the development of enzyme-specific IgE antibody before the onset of allergic symptoms. This allows for continuing interventions to reduce exposures, so as to minimize or eliminate those associated with symptoms. Workers with IgE to enzymes can still continue to work in the industry symptom-free for their entire career. This indicates that exposures needed to induce sensitization are different and probably lower than exposures needed to elicit enzyme allergic symptoms. The experience of the detergent enzyme industry in controlling occupational allergens can be applied to other industries. The detergent enzyme story can be viewed as a model for the control of type 1 protein allergens in the workplace.     

Exposure-response in occupational allergy

PURPOSE OF REVIEW: This review examines the relationship between exposure to workplace allergens and the risk of developing occupational allergy. RECENT FINDINGS: Evidence suggests that the risk of developing occupational allergy increases with allergen exposure; however, with some occupational allergens, this exposure-response relationship is more complex. In laboratory animal workers, the risk of developing occupational allergy increases with exposure, except at high allergen exposure when there is a reduction in sensitization. This attenuation of specific immunoglobulin E antibody is associated with increased specific immunoglobulin G4 antibodies, which are likely to play a protective role, leading to a form of natural tolerance. Exposure-response relationships are also very dependent on the genetic susceptibility of the individual. The interaction between genes, occupational allergens and other cofactors in the environment, such as endotoxin, are also important risk factors in the development of sensitization and asthma. SUMMARY: Occupational allergy provides a good opportunity to understand the complex relationships between exposure to allergens in the workplace, interaction with genes and the coexposures with other factors in the working environment and the increased risk of developing occupational allergy.     

Occupational allergy caused by carnation (Dianthus caryophyllus).

BACKGROUND: Occupational respiratory symptoms caused by decorative flowers are seldom reported in the literature. In our area a large portion of the population works in carnation (Dianthus caryophyllus) winter quarters, and many workers have symptoms of rhinitis and asthma related to exposition. OBJECTIVE: The purposes of this study were to investigate whether the symptoms induced by carnation were IgE-mediated and to study the possible allergens involved. METHODS: A total of 16 subjects employed in indoor carnation cultivation with symptoms during exposition time were studied along with 15 patients with allergic asthma who were not exposed to carnations and 15 healthy carnation workers used as control subjects. Skin prick tests with carnation extract and RASTs were performed. Protein bands were isolated by SDS-PAGE, and afterwards immunoblotting was performed to characterize the extract. Specific nasal provocation and nonspecific bronchial provocation tests were performed for all the asthmatic patients. Diurnal variation in peak expiratory flow was also measured. RESULTS: Skin prick test responses with carnation extract were positive in 15 of the 16 patients and negative in all control subjects. Nasal provocation test responses with carnation extract were positive in 13 of 16 patients. A significant correlation was seen between RAST and nasal provocation results (P <.01). Immunoblotting of sera from 13 patients showed 2 major IgE-binding fractions of 34 and 35 kd in most of the patients, which could constitute the major allergen. Methacholine PD20 showed a variable degree of nonspecific bronchial hyperresponsiveness in all asthmatic subjects. CONCLUSION: Data demonstrate the involvement of carnation in occupational allergy, mediated by an IgE-dependent mechanism.     

Asthma, skin symptoms, and allergy in a condom factory

BACKGROUND: Cases of occupational asthma have been reported in condom factories in the UK and France, but there has been no epidemiologic study of groups of workers in such factories. This investigation aimed to study the prevalence of symptoms in a Swedish condom factory, to determine groups at special risk, and to suggest preventive measures. METHODS: A questionnaire was mailed to 35 employees, 29 women and six men with mean ages of 37 and 32 years, respectively. All subjects were interviewed by a physician and underwent skin prick test with latex and epicutaneous testing with 39 substances, and blood samples were taken for allergy testing. RESULTS: Phadiatop was positive in 23%, RAST against Lycopodium in 31%, and RAST against latex in one of these 11. Ten subjects (29%) had work-related nose/eye symptoms; of these, eight had positive RAST to Lycopodium; three also had symptoms of occupational asthma and contact urticaria. Only one had positive RAST to latex. Five of the nine subjects with positive Phadiatop also had positive RAST to Lycopodium. All those with RAST positive to Lycopodium had worked in packaging, the area of the factory with the greatest exposure. The results of the patch tests did not correlate with the work-related symptoms. CONCLUSIONS: In a Swedish condom factory, there were a high prevalence of rhinoconjunctivitis and a small number of cases of asthma and contact urticaria caused by allergy to Lycopodium.