A rare case of allergic bronchopulmonary aspergillosis with allergic fungal rhinosinusitis masquerading as granulomatous vasculitis

The combination of allergic bronchopulmonary aspergillosis (ABPA) and eosinophilic granulomatosis with polyangiitis (EGPA) or Grnaulomatosis polyangitis (GPA) has been well described in the literature, but this is the first case report of ABPA with allergic fungal rhinosinusitis (AFRS) mimicking as granulomatous vasculitis (EGPA and GPA) as per the authors. A 25-year-old woman, symptomatic for the past 4 years and initially treated for bronchial asthma, presented with worsening dyspnea, cough, fever, anorexia, and leg pain. There were increasing pulmonary opacities in the chest radiograph, and a computed tomography scan demonstrated left hilar adenopathy and consolidation. The patient was diagnosed with ABPA after the initial workup and prescribed oral prednisolone with itraconazole. The patient also had nasal polyposis, sinusitis, mucin in sinuses, and fungal growth in mucin favoring the diagnosis of AFRS. Fiberoptic bronchoscopy showed plaque-like endobronchial lesions and bronchial stenosis, and histopathologic examination of the biopsy from the nodular lesion demonstrated eosinophilic bronchitis. Normal serum angiotensin-converting enzyme levels, positive Mantoux test, and the eosinophilic inflammation in the endobronchial biopsy ruled out the possibility of sarcoidosis. Both cytoplasmic and perinuclear antineutrophil cytoplasmic antibodies (c- and p-ANCA, respectively) were found positive in a vasculitis panel test, the positive p-ANCA favoring the diagnosis of EGPA, while the combination of endobronchial lesion, sinus abnormality, and nonresolving consolidation along with positive c-ANCA favoring the diagnosis of GPA as well. However, in the absence of histopathological evidence of vasculitis, ANCA may be false positive. Accordingly, a final diagnosis of ABPA combined with AFRS was made. The patient responded well to oral prednisolone along with inhaled asthma medications. Our case highlights the overlapping clinical features of eosinophilic lung diseases and small-vessel vasculitis, which may coexist, and the need to investigate thoroughly for better clinical outcomes.