Allergic vasculitis and granulomatosis, also known as allergic granulomatosis (AG), is also called allergic granuloma or allergic granulomatosis vasculitis. It is an autoimmune granulomatous vasculitis characterized by inflammation of small vessels in the lungs and system, extravascular granulomas and hypereosinophilia. It is a vasculitis characterized by asthma, eosinophilia and extravascular granuloma formation. The lesions mainly affect small and medium-sized arteries. Churg and Strauss first named this group of diseases allergic angiitis and granulomatosis in 1951. They believed that allergic factors play an important role in the occurrence of the disease. They distinguished this disease from PAN for the first time and proposed that this disease can be regarded as an intermediate type between PAN and Wegener's granulomatosis, or an intermediate type between Luffertius syndrome and Wegener's granulomatosis.