Allergic granulomatous angiitis and peripheral nerve lesion.

We examined 8 cases of allergic granulomatous angiitis (AGA). All cases showed peripheral nerve lesion, comprising damage of all myelinated fibers, which was more severe in larger ones. Immunofluorescent deposits of IgE were detected in the peripheral myelin. There was lymphocyte infiltration both around the endoneural capillaries and in the endoneurium, and an increase of endothelial cells. Nerve ischemia due to obstruction of the vasa nervorum, circulation insufficiency of the small vessels, or immunological abnormality through IgE may play a pathogenetic role in the peripheral neuropathy of AGA.