Asthma caused by mites encountered in agriculture


Occupations
  • Arboriculturist
  • Farmer
  • Gardener
  • Wine grower
Agents
Panonychus Citri, Panonychus ulmi, Plasmopara Viticola, Tetranichus Urticae.
 
Incidence
Incidence will vary from year to year. Subjects are usually atopic. IgE-dependent mechanism for subjects with respiratory symptoms. Irritation of an unknown origin is often also present. Symptoms are particularly common during the fruit picking season (autumn). There is common antigenicity between Tetranychus urticae, Panoncychus citri and Panonychus ulmi (respective inhibition between 83% and 71.6%). Concerning Dermatophagoides pteronyssinus and Tyrophagusputrescentiae, a partial cross-reactivity of 54.4% and 57.7% with Panonychus ulmi has been demonstrated. Furthermore, partial cross-reactivity exists between all these mites and Anisakis simplex. In farmers, sensitisation may occur throughout the year depending upon the work they are performing.
 
Conditions
Sensitisation to mite excretions in dust during particularly dry summers, and especially to tetranychus urticae (red spider mite). Similarly for Plasmopara viticola during humid autumnal periods (vines). Fungicides and pesticides may aggravate the condition. Fruit growers are most at risk: apples (panoncychus ulmi and tetranychus uritcae); lemons (paronychus citri). Additionally, 6% of farmers show sensitivity to Tetranychus urticae).
 
Symptoms
Rhinitis, spasmodic cough, conjunctivitis and asthma. Eczema, dermatitis and pruritus on exposed skin.
 
Diagnostic methods
Skin tests and bronchial provocation tests with the Panoychus Ulmi or Plasmophara viticola extracts (these extracts are not currently commercially available).

References

  1. Allergy, 2001,56:1157 - Astarita C. et al.
  2. Clin. Exp. Allergy 2001,31:1457 - Kim Y. et al.
  3. Allergy, 2001,56:660 - Johansson E. et al.
  4. Am Allergy Asthma Immunol 1999,82 : 223 Kim Y et al.
  5. J. Allergy Clin. Immunol. 1999,104:1285 - Yoon-Keun Kim et al.
  6. Clin. Exp. Allergy 1997,27:640 - Delgado J. et al.
  7. Clin. Exp. Allergy 1994,24:477 - Delgado J. et al.
  8. J. Allergy Clin. Immunol. 1994,93:457
  9. Rev. Fr. Allergol. 1977,17:93

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