Occupational asthma caused by soybean hull: a workplace equivalent to epidemic asthma

A case showing that soya hull exposure at work causes occupational asthma without flour-related bronchoconstriction.     

Occupational asthma caused by soybean flour in bakers—differences with soybean-induced epidemic asthma

BACKGROUND: Soybean dust has been identified as the causative agent of occupational asthma and asthma epidemics. Two main soybean hull allergens responsible for asthma outbreaks, Gly m 1 and Gly m 2, have been identified and purified. OBJECTIVE: The soybean allergens causing occupational asthma in exposed bakers were investigated and compared with those involved in epidemic asthma. METHODS: We report four bakers or confectioners with work-related respiratory symptoms who were exposed to soybean flour used as a baking additive. The causative role of soybean flour was investigated by immunological tests and specific inhalation challenge tests. Soybean flour allergens causing occupational asthma were characterized by immunoblotting. Immunoglobulin (Ig) E-reactivity to Gly m 1 and Gly m 2 was assessed using enzyme-linked immunosorbent assay. RESULTS: Sensitization to soybean flour was demonstrated by skin and serological tests and was confirmed by positive inhalation tests. Bronchial challenge test to soybean flour extract elicited immediate or dual asthmatic responses. Immunoblotting with soybean flour and soybean hull extracts showed IgE-binding mainly to high molecular weight (MW) allergens. There was an important individually different allergic response to inhalant soybean components. None of the patients showed IgE-reactivity against Gly m 1 and only one patient showed IgE-reactivity to the soybean hull allergen Gly m 2. CONCLUSION: These bakery workers had developed IgE-mediated occupational asthma to soybean flour. The allergens involved in occupational asthma caused by soybean flour are predominantly high MW proteins that are present both in soybean hull and flour, and they are different from the allergens causing asthma outbreaks, which are mainly low MW proteins concentrated in the hull.     

Occupational asthma caused by aromatic herbs

We describe a subject with occupational asthma caused by several aromatic herbs: thyme, rosemary, bay leaf, and garlic. The diagnosis was confirmed by specific inhalation challenges in the laboratory. Although immediate skin reactivity was demonstrated to the herbs the subject reacted to by inhalation, RAST showed that garlic was the most potent allergen by weight, the other herbs showing less reactivity. These aromatic herbs, bay leaf, thyme, and rosemary, should be included among agents causing occupational asthma in the food industry.     

Occupational asthma caused by inhalation of casein

Solutions of casein are usually sprayed over the leather in the final stage of tanning. We present the result of a thorough investigation of an atopic tannery worker with occupational asthma. Data from clinical record and metacholine challenges support the occupational source of the patient's symptoms, and positive bronchial challenge with casein clearly defines it as the specific aetiological agent. The presence of specific IgE suggests a hypersensitivity type I mechanism. In the tanning process chromium salts, paraphenylendiamine and formaldehyde have all been included as specific aetiological agents of asthma, but occupational asthma induced by inhalation of casein has not previously been reported.     

Occupational asthma caused by ethanolamines

Amino alcohols are used in various industries, often as minor constituents of compounds to modify the properties of the compound. Generally, they are considered to be safe, but they have been known to cause local skin irritation at higher concentrations in solutions. We report on three cases of occupational asthma caused by ethanolamines: two metal workers exposed to a cutting fluid containing triethanolamine, and one cleaner exposed to a detergent containing monoethanolamine. The diagnosis was based on work-related symptoms and on a chamber challenge with the suspected agent. Persistence of the symptoms after exposure ended was a common feature of the three cases.     

Occupational asthma induced by aniseed

This report deals with clinical and immunologic studies in a butcher with work-related asthma. Both the positive methacholine inhalation test and the significant changes observed in PEFR measurements supported the diagnosis of asthma. The significant fall observed in PEFR measurements when the patient handled aniseed supported the diagnosis of occupational asthma. Skin prick tests carried out with 13 spices showed positive reactions only to aniseed extract. The patient had high levels of specific antianiseed IgE antibodies. The bronchial challenge test with an aniseed extract showed an immediate response without a late response. These findings suggest that the respiratory symptoms in our patient were induced by the inhalation of aniseed dust through an IgE-mediated immunologic mechanism of immediate hypersensitivity. This study established the diagnosis of occupational asthma from aniseed dust sensitization.     

Occupational asthma caused by champignon flies

BACKGROUND: Occupational bronchial asthma in mushroom (champignon) workers is unusual, although reports on it appeared in 1938 and 1951; we have not found any others since those dates. Here we report the case of a 52-year-old man who works as a champignon cultivator. He suffered rhinoconjunctivitis and asthma attacks whenever he entered the champignon culture caves. We studied flies as a possible antigen source. We collected these insects from the growing sites in order to identify them, and then prepare an extract; the samples turned out to be of two families of insects of the order Diptera, 98% from the Phoridae family (Brachycera suborder) and 2% from the Sciaridae (Nematocera suborder). METHODS: Skin prick tests, conjunctival provocation tests, serum specific IgE, specific IgE-binding fractions in immunoblotting, and monitoring of PEFR (at work and off work) were performed. RESULTS: IgE-mediated hypersensitivity to these flies was demonstrated by skin prick test, conjunctival provocation test, serum specific IgE, and IgE-binding fractions in immunoblotting. Monitoring of PEFR both at work and off work showed a clear relationship between symptoms, or fall in PEFR, and the workplace. CONCLUSIONS: We report the case of a patient suffering from asthma and rhinoconjunctivitis caused by hypersensitivity to fly proteins.     

Occupational asthma and rhinoconjunctivitis caused by senna

Occupational sensitization to senna is seldom reported. We describe a 21-year-old male atopic factory worker who developed IgE-mediated asthma and rhinoconjunctivitis 5 months after exposure to senna while he was working for a company manufacturing hair dyes. In the bronchial challenge test with senna, he exhibited a strong reaction. The skin prick test gave a 12-mm wheal reaction. The radioallergosorbent test (RAST) with senna was highly positive (33.6 PRU/ml, class 4), and could not be inhibited with pollens or foods. In protein staining with SDS-PAGE, two heavy bands were detected in senna at about 14 and 25 kDa, and two faint bands were visible at 19 and 21 kDa. In IgE immunoblotting with the patient's serum, one heavy band was detected at about 16 and four faint bands at 23, 25, 28, and 38 kDa. The patient became symptom free after he had changed his job within the same company.     

Occupational asthma caused by inhalation of bovine serum albumin powder

Bovine serum albumin (BSA), which is present in bovine plasma, is one of the major allergens affecting patients with food allergies induced by milk and meat. It is also commonly used in research laboratories. Although some reports have documented food allergies associated with BSA, BSA-induced occupational asthma has not been reported. We report a case of occupational asthma and rhinitis in a laboratory worker caused by the inhalation of BSA powder, in which an IgE-mediated response was suggested as the pathogenic mechanism.