Fur mites induce dermatitis associated with IgE hyperproduction in an inbred strain of mice, NC/Kuj

An inbred strain of mice, NC, has been introduced as an animal model for at opic dermatitis because the mice develop dermatitis associated with severe scratch preceded by elevated serum IgE level when kept in conventional cond itions. Although hypersensitivity to some environmental factors is suggeste d to cause dermatitis; the precise factor remains unclear. As the mice main tained under conventional conditions were often infected with fur mites, we investigated whether an infection of fur mites induces skin lesions in NC. Infection with the fur mites induced NC to develop skin lesions associated with highly elevated serum IgE, whereas no obvious skin lesions were obser ved in BALB/c and C57BL/6, and the elevation of serum IgE level was minimal in these two strains of mice. The role of the fur mites in the manifestati on of skin lesions and IEE hyperproduction was confirmed by eliminating the fur mites by treatment with ivermectin. In addition, the existence of spec ific IEE antibody to Myocoptes musculinus antigen in the sera of mite-infes ted NC was detected by the antigen-induced histamine release from bone marr ow-derived cultured mast cells after sensitization with the serum. These re sults suggest that continuous exposure to fur mite antigen is a potential f actor in the development of dermatitis in NC. We provide a new model system of antigen-induced dermatitis for investigating the role of IgE in eliciti ng dermatitis. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.