Early recognition of eosinophilic granulomatosis with polyangiitis in outpatient settings: musculoskeletal and gastrointestinal clues beyond respiratory disease

Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystem immune-mediated disease characterized by adult-onset asthma, eosinophilic inflammation, and necrotizing vasculitis of small-to-medium-sized vessels. Diagnosis is frequently prompted by clinically overt neurological, cardiac, renal, cutaneous, or gastrointestinal involvement. However, potentially informative manifestations may already be recognizable earlier, particularly when asthma, chronic rhinosinusitis with nasal polyps, and blood eosinophilia coexist with otherwise nonspecific extrapulmonary findings. Most cohorts describe manifestations at diagnosis or during established disease and provide limited information on their early temporal appearance across different specialties. This gap is particularly relevant to arthralgia and myalgia, which are common but poorly characterized, and to eosinophilic gastrointestinal manifestations that may initially be classified as organ-restricted eosinophilic gastrointestinal disorders. Biopsy-proven myositis is rare but has occasionally been reported at presentation or before clinically recognizable neuropathy. This review examines early and potentially recognizable manifestations of EGPA across outpatient settings, with particular attention to musculoskeletal symptoms, objective muscle involvement, eosinophilic gastrointestinal disease, and the therapeutic implications of distinguishing organ-restricted eosinophilic disease from systemic EGPA.