Occupational allergy in an entomological research centre. I. Clinical aspects of reactions to the sheep blowfly Lucilia cuprina.

Twenty eight per cent (15) of 53 workers engaged in a sheep blowfly breeding programme designed to control genetically the pest Lucilia cuprina experienced allergic manifestations resulting from contact with this insect. The most common symptoms were rhinitis, affected eyes, rashes, and lower respiratory symptoms, usually, but not always, immediate in type. A personal history of non-insect related asthma, allergic rhinitis, or eczema, or a combination of these was more common in the fly allergic group but some workers experienced allergic symptoms only when exposed to the adult sheep blowfly. Raised levels of serum IgE antibodies specific for adult and larval allergens were found in approximately 70% of symptomatic workers, whereas only 30% and 7% of two groups of asymptomatic workers were found to have these antibodies. It is concluded that the sheep blowfly is an important source of airborne allergens and can prove a considerable occupational health hazard. Measures designed to reduce worker contact with blowflies and their emanations considerably reduced the incidence of allergic symptoms in the exposed workers.

Iodine-131 uptake in inflammatory lung disease: a potential pitfall in treatment of thyroid carcinoma.

A mixed differentiated thyroid carcinoma was found in a small asymptomatic nodule in a 44-yr-old woman with recurrent chest infections and bronchiectasis. After total thyroidectomy and 162 mCi (6 GBq) radioiodine ablation there was uptake in the thyroid remnant and in both lungs, interpreted as lung metastases. In 2 years she received further three 162 mCi (6 GBq) doses of 131I, as scans showed very similar lung activity. Another scan, during thyroxin suppression, showed again activity in the lungs. A 47-yr-old male patient with similar respiratory disease and no history of thyroid disorder volunteered to undergo radioiodine scan while on triiodothyronine suppression. His scan, too, showed concentration in the lungs. The female patient died 7 years after the diagnosis of lung thyroid metastases was made. No metastasis was found at autopsy. Radioiodine lung uptake may occur in patients with chronic inflammatory lung disease, presenting a potential diagnostic pitfall in patients with differentiated thyroid carcinoma.

Inhalant allergy following occupational exposure to blowflies.

An allergic reaction, provoked by exposure to the blowfly Lucilia cuprina and shown to be IgE-mediated, occurred in a subject employed in an entomological research laboratory. The subject's serum, and sera from three other asthmatic patients with IgE antibodies to blowfly extracts, also reacted with extracts from the screw-worm fly (Chrysomya bezziana). Results suggested that antigens from the two species share immunological cross-reactivity. Cross-reactions also exist between the different developmental stages of both species. Allergic reactions to inhaled insect allergens may not be uncommon in the Australian community.

Peripheral pooling of bronchographic contrast material: evidence of its relationship to smoking and emphysema.

Sixty-six subjects, mainly derived from various occupational groups and one-third of whom admitted to dyspnoea on exertion, have been grouped according to the appearance of their peripheral airways at bronchography with oily propyliodone. Eleven subjects showed marked peripheral pooling of radiographic contrast material, 22 showed mild or moderate pooling, and in 33 peripheral pools were absent. Pooling was not seen in non-smoking subjects. In the group of subjects without pooling, pulmonary function in non-smokers and subjects with a history of smoking was similar. Subjects with marked pooling had a significantly lower pulmonary diffusing capacity (transfer factor) and evidence of loss of pulmonary elastic recoil when compared with subjects with absent peripheral pooling. These results indicate that bronchographic peripheral pooling is associated with the physiological changes of panacinar pulmonary emphysema and suggest that a causal relationship may exist between the organic bronchiolar lesion of pooling and the peripheral parenchymal lesion of panacinar emphysema.

Bronchial walls in the radiological diagnosis of asthma.

Although bronchial wall thickening is known to occur in asthma, its radiological visibility and significance are matters of dispute. The present study shows that thickening can be detected in the plain chest radiographs of patients with severe asthma, but it cannot be reliably detected in patients with mild asthma. Measurements of bronchi made on lung tomograms showed that the lumen-wall ratio more clearly separated the asthma and normal groups than did observation of bronchial wall thickness alone.