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Equine insect bite hypersensitivity: What do we know?

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from pubmed: horse by Schaffartzik A, Hamza E, Janda J, Crameri R, Marti E, Rhyner C

Equine insect bite hypersensitivity: What do we know?

Vet Immunol Immunopathol. 2012 Apr 3;

Authors: Schaffartzik A, Hamza E, Janda J, Crameri R, Marti E, Rhyner C

Abstract
Insect bite hypersensitivity (IBH) is an allergic dermatitis of the horse caused by bites of insects of the genus Culicoides and is currently the best characterized allergic disease of horses. This article reviews knowledge of the immunopathogenesis of IBH, with a particular focus on the causative allergens. Whereas so far hardly any research has been done on the role of antigen presenting cells in the pathogenesis of IBH, recent studies suggest that IBH is characterized by an imbalance between a T helper 2 (Th2) and regulatory T cell (T(reg)) immune response, as shown both locally in the skin and with stimulated peripheral blood mononuclear cells. Various studies have shown IBH to be associated with IgE-mediated reactions against salivary antigens from Culicoides spp. However, until recently, the causative allergens had not been characterized at the molecular level. A major advance has now been made, as 11 Culicoides salivary gland proteins have been identified as relevant allergens for IBH. Currently, there is no satisfactory treatment of IBH. Characterization of the main allergens for IBH and understanding what mechanisms induce a healthy or allergic immune response towards these allergens may help to develop new treatment strategies, such as immunotherapy.

PMID: 22575371 [PubMed – as supplied by publisher]

 

Comment:  Progress on an old age problem.  Always known by deduction,  Culicoides spp. cause dramatic skin reactions in the horse.  The feeding process of Culicoides leaves some horses with profound swelling and intense itching.  To date, teh most effective tool has been exogenous steroid therapy.  As with many mysteries, the first step in the unlocking process is more understanding.  Perhaps hyposensitization therapy is in the future.