Allergy to inhaled egg material

Occupational protein contact dermatitis: two case reports

Protein contact dermatitis (PCD) is a contact dermatitis caused by high-molecular-weight proteins. This entity has been reported with increasing frequency, most commonly as occupational hand dermatitis in food handlers. Clinically, it is characterized by a chronic and recurrent dermatitis with erythema, scaling, and fissures with acute exacerbations occurring a few minutes after contact with offending allergen. We report two cases in confectioners who presented with chronic hand dermatitis.

Allergic reactions to foods by inhalation

Although allergic reactions to foods occur most commonly after ingestion, inhalation of foods can also be an underlying cause of these reactions. For example, published reports have highlighted the inhalation of allergens from fish, shellfish, seeds, soybeans, cereal grains, hen's egg, cow's milk, and many other foods in allergic reactions. Symptoms have typically included respiratory manifestations such as rhinoconjunctivitis, coughing, wheezing, dyspnea, and asthma. In some cases, anaphylaxis has been observed. In addition, there have been many investigations of occupational asthma following the inhalation of relevant food allergens. This report reviews the current literature focusing on allergic reactions to foods by inhalation.

Specific immune response to occupational antigens in asymptomatic egg processing workers

BACKGROUND

Hen's egg proteins are known sensitizers and may cause occupational respiratory diseases in exposed workers. The study was conducted in order to ascertain the prevalence of sensitization to work-related antigens in asymptomatic egg processing factory workers.

METHODS

Clinical history, respiratory function, atopy and the presence of specific antibodies to environmental and occupational antigens were evaluated in 77 workers. A total of 116 unexposed and non-professionally exposed controls were also studied. The antigen concentration of the factory environment was measured.

RESULTS

Specific IgE and precipitin positivity to egg components was more frequently present in workers than in the two control groups. The egg white protein concentration was higher in the egg breaking area.

CONCLUSIONS

The avian proteins inhaled induced immune responses to occupational antigens in asymptomatic, professionally exposed subjects. Measures to decrease environmental antigen concentrations and thorough clinical monitoring of sensitized workers are advocated.

Cold-attenuated live influenza vaccines, a risk-benefit assessment

The principle of live attenuated influenza vaccines has been known for many decades. However, the pharmaceutical and clinical development according to current regulations, of modern live influenza vaccines based on cold adapted influenza viruses (CAIV) started only recently and these vaccines will most probably become an alternative within the next couple of years to licensed inactivated influenza vaccines that have been used routinely since the early 1940s. In contrast to contemporary trivalent inactivated influenza vaccines, which are administered intramuscularly, trivalent CAIV-based vaccines will be administered intranasally as a spray. Quality, safety and efficacy aspects related to CAIV vaccines as well as possible risks linked to the widespread use of these vaccines will be discussed in the following overview and compared to established influenza vaccines. Moreover, issues of practicality of CAIV vaccines focusing on the necessity of an annual update of influenza vaccines are addressed.

Unusual presentations of food allergy

OBJECTIVE

This presentation is designed to critically review information on presentations of food hypersensitivity reactions that may be considered unusual regarding the source or nature of allergen, route of exposure, or clinical manifestation.

DATA SOURCES

Information has been gathered primarily through a thorough search of the English literature relevant to human subjects. Some clinical cases were also included from the author's own clinical experience.

STUDY SELECTION

Information summarized here was critically selected on the basis of proven or acceptable scientific validity.

RESULTS

The findings indicate that food allergy presentation can be unusual in three main aspects. First, the offending allergen may not be the obvious food that was ingested or be a food protein incorporated in a nonfood product. Second, systemic reactions can be provoked by very minute quantities of food allergens that may even get access through noningestant routes, eg, inhalation, odor, skin contact, or mucous membrane contact. Third, the clinical manifestations are not limited to the few gastrointestinal, cutaneous, and respiratory symptoms with which we are generally familiar.

CONCLUSIONS

The extent of food allergy presentation is more than has been generally realized. Our awareness of such unusual presentations adds new knowledge and should prompt our interest in carefully evaluating patients with obscure allergic reactions for possible food allergy.

Respiratory symptoms and ventilatory function in confectionery workers

Respiratory symptoms and ventilatory capacity were studied in a group of 288 workers (259 women and 29 men) employed in a confectionery plant. A group of workers (96 women and 31 men) not exposed to confectionery manufacture were also studied as controls. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being greatest for confectionery workers exposed to the dust of flour, talc, and starch and the vapours of alcohol. Chronic bronchitis was reported by 7% of the women and 21% of the men, and chest tightness was reported by 27% of women and 66% of men. There was a high prevalence of acute irritative symptoms during the workshift in all groups of confectionery workers, especially for cough, dyspnoea, burning and dryness of the throat, and eye irritation. For all groups of confectionery workers there were statistically significant across shift reductions in ventilatory capacity, being most pronounced for maximum flow rate at 50% of the control vital capacity (FEF50; range 4.6-13.0%) and at 25% of the control vital capacity (FEF25; range 4.7-22.3%). Preshift values of FEF50 and FEF25 were significantly lower than predicted values. The data suggest that some workers employed in confectionery plants may develop acute and chronic respiratory symptoms associated with changes in lung function.

Occupational asthma

Occupational asthma is recognized as the most common form of occupational lung disease. Over 200 causative substances have been described. Major cases of occupational asthma are discussed along with valuable diagnostic approaches. Early diagnosis and removal of the patient from workplace exposure to the causative substance can prevent progression to severe asthma.

Evaluation of occupational asthma from airborne egg protein exposure in multiple settings

We previously reported IgE-mediated occupational asthma among workers exposed to airborne egg protein at a plant that produces liquid and dried powdered egg products. To demonstrate that our original observations are generalizable to other facilities that process eggs, and to estimate the prevalence of IgE-mediated occupational asthma among egg-exposed workers, we conducted surveys at two additional plants. We administered a questionnaire to 188 employees to identify workers with symptoms suggestive of occupational asthma. We further evaluated 88 workers with and without symptoms by a clinical examination by a physician blinded to results of other tests, serial peak expiratory flow rate (PEFR) determinations every three hours while awake for one week, and skin prick tests and serum specific IgE levels to extracts of factory egg products, commercial egg test reagents, and egg white protein fractions. Fourteen workers had work-related asthmalike symptoms by questionnaire, a physician diagnosis of occupational asthma, and evidence of IgE-mediated sensitization to one or more egg proteins. Workers exposed exclusively to liquid egg aerosol, as well as workers exposed primarily to dried airborne egg protein, developed occupational asthma. This study replicated our original observations and demonstrated that workers in all areas of liquid and powdered egg production are at risk of developing occupational asthma from exposure to airborne egg proteins.

Ispaghula sensitization in workers manufacturing a bulk laxative

Exposure to ispaghula dust in a pharmaceutical factory resulted in chest tightness/wheeze, nasal, and ocular or skin symptoms in 48 of 92 exposed workers. Whilst symptoms were not incapacitating in the majority (44) of these, one worker required antihistamines and three others experienced severe respiratory symptoms when exposed to the dust. These three were atopic, had a positive RAST and skin test to ispaghula; a combination unique to them. There was a significant relationship between work-related symptoms and atopic status, however, smoking did not influence symptoms, total serum IgE and specific anti-ispaghula IgE. We conclude that handling ispaghula produces an irritant effect in most exposed people, however, sensitization to the dust can occur with severe respiratory symptoms.

Respiratory function in animal food processing workers

A group of 71 men employed in animal food processing was studied to assess the prevalence of acute and chronic respiratory symptoms and the presence of lung function abnormalities. In addition, a control group of 55 unexposed men was studied for the prevalence of chronic respiratory symptoms. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed workers compared to the control workers. Those workers who smoked had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than the smokers in the control group. For nonsmokers, the differences between exposed and control workers were significant for chronic phlegm and chest tightness. The frequency of acute symptoms associated with the work shift was high among the animal food workers. There were significantly lower measured values for FVC, FEV1, and FEF50 in the exposed group (smokers and nonsmokers) compared to predicted lung function values. In smokers, all measured parameters of ventilatory capacity were significantly less than predicted; for nonsmokers, the FVC and FEV1 were less than normal. Our data indicate that exposure to dust in the animal food industry may be associated with the development of acute and chronic respiratory symptoms and the impairment of lung function. Smoking, in this setting, appears to aggravate these changes.

Anaphylaxis caused by inhaled pavlova mix in egg-sensitive children

Two cases of anaphylactic reactions that occurred in young children with clinical hypersensitivity to egg protein after their exposure to a pavlova mix (which contains powdered egg-white) are described. The exposure took place when a packet of pavlova mix was opened and its contents were transferred into a bowl by adults. Although the children were in the same room, no direct contact was made. This indicates that the exposure occurred by way of the inhalational route. Clinical sensitivity to eggs is common in infancy and early childhood. Parents of children who have experienced immediate hypersensitivity reactions to egg-protein should be aware of the potential hazard of pavlova mixes and other sources of egg-white powder.

Antibodies to bird serum proteins in confectionery workers exposed to egg spray

In an extended study of group of confectionery workers sensitized by exposure to egg spray, it was found that their blood serum contained antibodies to avian serum proteins. Comparison of the ratio of IgG antibodies determined by ELISA to egg yolk 'livetins' and pigeon serum in these patients and in pigeon breeders showed that the phenomenon is entirely due to immunological cross-reactivity among avian blood serum proteins. These avian serum proteins in hens' eggs, not ovalbumin, were identified as the major sensitizing antigens.

Occupational asthma from inhaled egg protein

We evaluated workers and performed an industrial hygiene assessment at a plant where raw eggs are processed into powdered egg yolk and whole egg. Egg dust levels in the packaging room straddled the American Conference of Governmental Industrial Hygienists' (ACGIH) exposure guideline of 10 mg/m3 for nuisance dust. We obtained medical histories from 25 workers, and performed physical examinations, spirometry, and serial determinations of peak expiratory flow rate (PEFR) by portable meter every 3 hrs (while awake) for 7 days. We defined symptomatic bronchial lability to be a decrement in PEFR on any one day of 20% or more of the day's maximum, with concurrent symptoms. Skin-prick tests and serum assays for specific IgE by the radioallergosorbent (RAST) method were performed to assess sensitivity to commercial egg proteins, egg protein fractions, and freshly prepared extracts of whole egg powder and yolk. We classified participants as definite cases of asthma if both the examining physician diagnosed asthma and symptomatic bronchial lability was demonstrated by serial PEFR determinations. Definite noncases of asthma were those participants in whom the physician did not diagnose asthma and in whom symptomatic bronchial lability was not demonstrated by PEFR. All five definite cases, compared to three of 16 definite noncases of asthma, had one or more positive skin-prick tests to egg proteins. Four of five cases, compared to 0 of 14 noncases, who had serum determinations, had an elevated RAST to one or more of the egg proteins. This study demonstrates that occupational asthma associated with IgE-mediated allergy to egg proteins occurs among workers exposed to inhaled egg proteins.

Antibodies against hen's egg proteins in pigeon breeder's disease

The serum of patients with pigeon breeder's lung (PBL) contains IgG-class antibodies against pigeon serum proteins. These antibodies cross-react strongly with the sera of other avian species. Cross-reactivity, as demonstrated by precipitation, complement fixation, haemagglutination and microELISA, is also exhibited with the water-soluble proteins in hen's egg yolk and egg white. The phenomenon appears to be due to the presence of hen serum proteins in the eggs, which occur particularly concentrated among the water-soluble proteins in the yolk ('livetins'). It is proposed that anti-egg antibodies may explain the frequent serological finding of 'false-positive' asymptomatic pigeon breeders.

Skin-test reactivity to egg protein--exposure by inhalation compared with ingestion

Of two hundred and sixty-seven subjects exposed to egg by ingestion only, forty-eight were skin (prick)-test positive to egg material. All forty-eight subjects also reacted to other allergens on skin testing, forty-seven (98%) to allergens associated with respiratory allergy. Of thirteen subjects exposed to egg by inhalation in their workplace (and ingestion) two were skin-test-positive to egg, both also reacting to respirable allergens. Thus, inhalation of egg antigen does not greatly influence skin-test reactivity to eggs as determined by comparing the ratio of egg skin-test-positives to total skin-test-positives in the egg groups ingesting and inhaling egg antigen, i.e. 48:218 vs 2:6. In terms of the pulmonary response to inhaled eggs there were equal numbers of symptomatics with positive skin tests to common allergens as there were symptomatics with negative skin tests. Thus, an allergic predisposition shown by a positive skin test to common allergens does not predict nor preclude development of a pulmonary reaction to inhaled egg material.