Eosinophilic Granulomatosis With Polyangiitis
• This is a rare disease that affects men and women equally. Clinical presentation can be divided into three phases. First is a prodromal phase characterized by allergic rhinitis, sinusitis, nasal polyposis, and asthma.
Second phase is characterized by peripheral blood and tissue eosinophilia and the third phase consists of small vessel vasculitis manifestations similar to GPA with a higher rate of cardiac involvement.• Diagnostic approach is similar to GPA and MPA; 50% will be ANCA positive (commonly MPO). In addition, patients will have eosinophilia (usually 5000-9000 eosinophil/uL) and elevated immunoglobulin E levels. Tissue biopsies show microgranulomas, fibrinoid necrosis, and thrombosis of small vessels with eosinophilic infiltrates.
• Treatment for EGPA has some similarities to GPA, but additional treatments targeting IL-5 and IgE are used. Treatment approach includes glucocorticoids at the same dose as GPA ± cyclophosphamide if severe life-threatening manifestations are present. Maintenance treatment options are the same as GPA. Anti-IL-5 therapy with mepolizumab at the dose of 300 mg every 4 weeks has been recently approved for treatment of EGPA. IL-anti-IgE therapy with omalizumab is also beneficial for EGPA with primarily asthma and sinonasal disease.27