Peripheral nerve, Churg-Strauss

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) is a vasculitis of small and medium sized arteries. Lung, skin, and peripheral nerves are most commonly affected but it may involve the cardiovascular, gastrointestinal, renal, and central nervous systems. PNS involvement typically presents as mononeuritis multiplex. Microscopically, blood vessels show an eosinophil-rich inflammatory infiltrate in the vessel wall, often with fibrinoid necrosis. Granulomas are occasionally seen. Treatment is generally with steroids and other immunosuppressive agents.