Angiostrongyliasis infection masquerading as granulomatosis with polyangiitis: a case-based review

Pulmonary angiitis is a small vessel vasculitis commonly reported in granulomatosis with polyangiitis (GPA) but is rarely attributed to angiostrongyliasis. We report a case of a patient with well-controlled rheumatoid arthritis, who was treated for GPA based on lung biopsy results with glucocorticoids (GC). Upon re-review of the initial pathology, along with peripheral eosinophilia and history of recent travel, the patient was eventually diagnosed with angiostrongylus-like nematode infection. GCs were subsequently discontinued and instead, the patient was treated with anthelmintics with complete resolution of symptoms. Commonly associated with eosinophilic meningitis or abdominal angiostrongyliasis in humans, clinical pulmonary manifestations of this parasite species are rare. With parasitic infiltration of the pulmonary vessels mimicking clinical GPA, diagnosis and treatment can be difficult in these patients. We discuss the third-reported case and first-reported survivor of Angiostrongylus-induced pulmonary angiitis followed by a focused review of the literature.