The term "relapse" is used to indicate disease related inflammation that has the potential to cause organ injury and requires treatment. Determination of a relapse is based upon the finding of disease-related inflammation. The evidence for this comes from review of symptoms, physical examination, laboratory tests, and sometimes imaging studies. Relapses must be differentiated from damage, infection, medication side effects, or other problems that can cause similar symptoms or laboratory abnormalities. Relapse manifestations and frequency vary for each form of vasculitis and have been determined based on studies published in the medical literature.
Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss)
It can be hard to determine relapses in Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss). A return of sinus symptoms and asthma is very common, but these but may not represent active vasculitis. These symptoms may require treatment with prednisone and are commonly the rate-limiting features in being able to reduce the prednisone dose in Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss). Relapses of vasculitis in Eosinophilic Granulomatosis with Polyangiitis are less common and have been reported in ranges from 10-30%
Giant cell arteritis
Reported relapse rates in giant cell arteritis have ranged from 50-90%.
Reported relapse rates in microscopic polyangiitis have ranged from 40-60%.
Reported relapse rates in polyarteritis nodosa have ranged from 10-30%.
Reported relapse rates in Takayasu’s arteritis have ranged from 50-80%.
Granulomatosis with polyangiitis (Wegener’s)
Reported relapse rates in granulomatosis with polyangiitis (Wegener’s) have ranged from 50-70%.