title: Equine intradermal test threshold concentrations for house dust mite and storage mite allergens and identification of stable acari fauna.
abstract: BACKGROUND
  House dust mite (HDM) and storage mite (SM) stable fauna and their associated equine intradermal test (IDT) threshold concentrations (TCs) for the midwestern region of the USA are unknown.
  
  
  OBJECTIVE
  To determine IDT TCs and serum IgE concentrations for two HDM and three SM species in clinically normal horses over two seasons, and to identify the mite taxa and habitats in a stable.
  
  
  METHODS
  Thirty-eight clinically normal horses.
  
  
  METHODS
  Threshold concentrations for HDMs and SMs were determined using IDT subjective measurements and a statistical model. An enzyme-linked immunosorbent assay was used to quantify serum IgE concentrations for the same mite species. A modified flotation method was used to identify morphologically HDMs and SMs.
  
  
  RESULTS
  Subjective IDT TCs were as follows: 1:80,000 w/v for Dermatophagoides farinae in both seasons; 1:80,000 w/v in spring and 1:160,000 w/v in late summer for Dermatophagoides pteronyssinus; 1:40,000 w/v in spring and 1:20,000 w/v in late summer for Acarus siro; 1:20,000 w/v for Lepidoglyphus destructor in both seasons; and 1:20,000 w/v in spring and 1:10,000 w/v in late summer for Tyrophagus putrescentiae. Statistically significant associations for increased serum IgE and a positive IDT reaction were evident for D. farinae in the spring and D. pteronyssinus in both seasons. One mite from all four genera specific to this study was identified; however,two HDM and A. siro species were not detected.Conclusions and clinical importance – This study established HDM and SM IDT dilution concentrations for the horses in this region. Exposure to diverse acaridae fauna may contribute to the pathogenesis of equine allergic disease.
authors.forename: Holly A
authors.initials: HA
authors.lastname: Roberts
authors.forename: Samuel D A
authors.initials: SD
authors.lastname: Hurcombe
authors.forename: Andrew
authors.initials: A
authors.lastname: Hillier
authors.forename: Gwendolen
authors.initials: G
authors.lastname: Lorch
mesh_terms: D040041:Acaridae / Q000276:immunology*; D000485:Allergens / Q000276:immunology*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis / Q000276:immunology*; D006736:Horses; D007428:Intradermal Tests / Q000592:standards / Q000662:veterinary; D008297:Male; D039981:Pyroglyphidae / Q000276:immunology*; D012621:Seasons
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides