Asthma caused by dust mites in barns


Occupations
  • Baker
  • Farmer
  • Food industry
  • Miller
Agents
Acarus farris, Acarus siro, Blomia Kulagini, Dermatophagoides pteronyssinus, Euroglyphus Maynei, Glycyphagus domesticus, Leptidoglyphus destructor, Tyrophagus putrescentiae.
 
Incidence
Incidence: dependent on co-factors: smoking, atopy and a predisposition to bronchial hyperreactivity.
 
Non-atopic subjects may also be affected.
 
IgE-dependent mechanism
Many subjects who are sensitised to storage mites also show sensitivity to Dematophagoides pteronyssimus.
 
Conditions
The degree of humidity in the cereal before storage favours multiplication of mites: proper ventilation is therefore important. In the food industry, certain types of mites (storage mites) may contaminate foodstuffs:

- cheese (Acarus Siro, Blomia Kulagini),
- chorizo (Euroglyphus Maynei),
- garlic and Ham (Tyrophagus Putrescentiae and Acarus Siro).
 
The response to TDI is regulated by the MHC class II loci DQA1 and DQB1.
 
Symptoms
Rhinitis and asthma symptoms are concomitant and persist after work has stopped.
 
Diagnostic methods
Skin prick test for various species of mite for which extracts are commercially available.
 
Immunological dosage: RAST/CAP RAST.
 
Bronchial provocation tests (in hospital) reveal both immediate and delayed reactions.

Recent studies on sputum induced during bronchial provocation tests have shown that measurement of ECP and Tryptase may act as additional diagnostic factors.

References

  1. Allergy 1999,54:884 - Alvarez MJ. et al.
  2. Allergy 1999,54:769 - Marcos Bravo C. et al.
  3. J . Invest. Allergol. Clin. Immunol. 1997,7:407 - Armentia. A. et al.
  4. J. Allergy Clin. Immunol.1984, 84:108
  5. J. Allergy Clin. Immunol. 1989,84:296
  6. Ann. Appl. Biol. 1976,82:180
  7. Clin. Allergy 1981,11:217
  8. Clin. Allergy 1985,15:555
  9. Clin. Allergy 1979,9:229

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