IgE-associated cells in the specimens of 25 allergic and non-allergic subjects were stained by the peroxidase technique with the use of a polyclonal antiserum. The technique is described and its advantages over the immunofluorescence procedures are shown. In each allergic subject IgE-associated cells could be stained, whereas no cells could be found in non-atopic subjects after suppressing non-specific background staining (Fig. 4). Therefore, this method allows to distinguish between IgE-mediated allergic diseases of the nasal mucosa and diseases of other pathomechanisms. The stained cells formed a specific distribution pattern with a typical accumulation in the subepithelial and epithelial layer (Fig. 2), whereas only few cells were found in the mucosal glands.