Eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss syndrome) is a small vessel vasculitis without immune complexes associated with asthma, eosinophilia, and antibodies against neutrophil myeloperoxidase (also known as p-ANCA).
EGPA refers to the combination of primary vasculitis with eosinophilic vasculitis, late-onset asthma, and multisystemic involvement. Histopathologically, it is marked by allergic angiitis and granulomatosis. Any organ system can be affected, but lung involvement (severe asthma) is almost always present. Skin lesions occur in up to 50%-70% of cases. Other commonly affected organs include the nervous system (mono- and polyneuropathy), heart, kidneys, and abdominal viscera.
Sharma et al. review the range of systemic vasculitides, including EGPA. The report that the ANCA-associated vasculitides include Churg-Strauss syndrome (EGPA), microscopic polyangiitis, and granulomatosis with polyangiitis (Wegener's granulomatosis). Either type of ANCA (cytoplasmic or perinuclear) may occur in a patient with ANCA-associated small vessel vasculitis, but perinuclear ANCA is typically found in EGPA.
As discussed by Bosch et al., the primary therapy for EGPA is immunosuppression with systemic glucocorticoids. An additional immunosuppressive agent can be added in patients with more advanced or refractory disease and in those whose disease flares with tapering of systemic glucocorticoids.
Illustration A shows eosinophilic vasculitis consistent with EGPA.
Answer 1: Allergic bronchopulmonary aspergellosis (ABPA) is caused by hypersensitivity to Aspergillus fumigatus and characterized by poorly-controlled asthma, recurrent pulmonary infiltrates, eosinophilia and bronchiectasis, but is NOT associated with p-ANCA.
Answer 3: Cystic fibrosis (CF) is an autosomal recessive genetic disease affecting respiratory, gastrointestinal, and reproductive systems. CF is not associated with eosinophilia or ANCA.
Answer 4: Paragonimus westermani infection is a food-borne parasitic infection caused by a lung fluke. It can cause a subacute to chronic inflammatory disease, it is not associated with ANCA.
Answer 5: A Pancoast tumor refers to a tumor of the pulmonary apex, typically non-small cell lung cancers. Eosinophilia and ANCA positivity are not present.
Sharma P, Sharma S, Baltaro R, Hurley J. Systemic vasculitis. Am Fam Physician. 2011 Mar 1;83(5):556-65. Review. PubMed PMID: 21391523.
PMID:21391523 (Link to Abstract)
Bosch X, Guilabert A, Espinosa G, Mirapeix E. Treatment of antineutrophil cytoplasmic antibody associated vasculitis: a systematic review. JAMA. 2007 Aug 8;298(6):655-69. Review. PubMed PMID: 17684188.
PMID:17684188 (Link to Abstract)
USMLE World Step 1 QBank Question #667. Copyright © USMLEWorld, LLC 2012.