Baker's asthma


Baker's, pan cake maker's, pizza maker's asthma 

Occupations

  • Animal breeder
  • Baker
  • Cook
  • Flour milling
  • Food industry
  • Pancake maker
  • Pastry cook
  • Pizza maker

Agents
Alpha amylase, Alternaria, Arthropodes, Aspergillus, Barley, Buckwheat, Ephestia, Glucoamylase, Hemicellulase, Lupin, Oats, Pollens, Rye, Saccharomyces cerevisiae, Sesame, Soya, Tribulium confusum, Wheat, Xylanase.

Incidence
Incidence: between 5 to 24% of subjects may be affected according to different researchers. Atopy is an almost constant factor. The mechanism is IgE-dependent, however, there are other phenomena causing irritation and some which release histamine directly (lectins). In Europe, bakers' asthma is the second most frequent cause of occupational asthma.

The use of monoclonal antibodies for the detection of allergens in the workplace environment seems to be reliable. It could be used in the design of preventive measures.

Smoking and the concentration of dust in the workplace are aggravating factors.

Conditions
The exposure to the risk is greater in poorly ventilated traditional bakeries than in modern industrial bakeries. The measurement of flour antigens in the bakery is the most specific test for occupational exposure levels. After wheat flour (alpha amylase), soya flour is the most frequent cause. Sensitization to Ephestia and other arthropods are due to contamination. Cross-reactivity exists between Ephestia (lepidoptera) and Dermatophagoides pteronyssinus. Allergy to tribolium (coleptera) is due to its presence in old flour. The characterization of different allergens found at the workplace has permitted the identification of alpha-amylase (14 to 18 kDa) as well as Acyl-CoA oxydase (26 kDa), a peroxydase (36 kDa) and a fructose diphosphate aldolase (37 kDa). Demand for different types of bread leads to new sensitisations to unexpected allergens, such as lupin, sesame and poppy. Amongst the most frequently used additives, xylanase and cellulase can give rise to true sensitisations with reactions to alpha amylase. Occupational asthma due to lupin flour has been described in agronomy researchers.

Symptoms
Asthma is almost always preceded by rhinitis. Classical asthma, associated with a cough, initially linked to the work place, but becoming permanent, frequently associated with conjunctivitis.

Tribolium sensitisation appears as intense urticaria on the exposed parts of the skin.

Diagnostic methods
Skin prick test or IDR for flour and alpha-amylases.

Immunological assays: RAST/CAP RAST to alpha-amylase, various flours and moulds.

Bronchial provocation tests (in hospital) is important.

References

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As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.