Eosinophilic Granulomatosis With Polyangiitis (Churg-Strauss)

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic, eosinophil-rich small-vessel vasculitis. It is associated with Th2 immune activity and increased interleukin-5 production, which promotes eosinophil activation and survival. Activated eosinophils enter tissues, contribute to granulomatous inflammation, and damage small blood vessels through necrotising vasculitis. The pattern that should catch a nurse’s attention is adult-onset or difficult-to-control asthma plus eosinophilia plus disease outside the airways. Allergic rhinitis and nasal polyps often precede the systemic illness. Pulmonary infiltrates, skin lesions, gastrointestinal symptoms, peripheral neuropathy, renal abnormalities, or cardiac disease indicate that this is more than severe asthma. EGPA is often described in three phases: - Prodromal phase: asthma, allergic rhinitis, or nasal polyposis. - Eosinophilic phase: marked blood eosinophilia with eosinophilic infiltration of organs, particularly the lungs, gastrointestinal tract, or heart. - Vasculitic phase: vascular inflammation causing injury to the skin, nerves, kidneys, lungs, heart, or other organs. These phases can overlap, recur, or appear out of order. A patient does not need to display a neat sequence. ANCA testing helps define the phenotype but does not rule EGPA in or out...