Allergic angiitis, also known as Churg-Strauss syndrome or eosinophilic granulomatosis with polyangiitis, is a rare autoimmune disorder where the blood vessels get inflamed and cause a host of symptoms such as difficulty in breathing, skin rash, fever, and weakness. In medical terms, it is known as vasculitis. Apart from these medical names, there are certain synonyms for this condition which are sometimes used by healthcare professionals. Some common synonyms are allergic granulomatosis, Churg-Strauss granulomatosis, eosinophilic vasculitis, and Churg-Strauss vasculitis. Whatever the name, it is important to get early diagnosis and treatment to avoid any complications.