Title : Eosinophilic granulomatosis with polyangiitis presenting as mononeuritis multiplex in a patient with longstanding asthma
Abstract:
Eosinophilic Granulomatosis with Polyangiitis (EGPA), previously known as Churg-Strauss Syndrome, is a rare systemic autoimmune vasculitis affecting small to medium-sized vessels. It is characterized by a triad of asthma, eosinophilia, and necrotizing vasculitis, and typically presents in individuals between the ages of 40 and 60. EGPA is a multisystem disorder that may involve the lungs, heart, skin, gastrointestinal tract, and peripheral nervous system. Neurological manifestations, particularly mononeuritis multiplex, are common and may significantly impair quality of life.
We present the case of a 59-year-old female with a 15-year history of bronchial asthma who developed paraesthesia and progressive weakness in the right upper and lower limbs, culminating in wrist and ankle drop. On examination, she demonstrated distal sensory deficits and motor weakness consistent with mononeuritis multiplex. No skin involvement or cranial nerve abnormalities were noted. Laboratory investigations revealed leukocytosis with marked eosinophilia (76.6%) and elevated inflammatory markers. Autoimmune screening was notable for positive p-ANCA, while ANA and RF were negative. Nerve conduction studies revealed a sensorimotor polyneuropathy with predominant axonal features. Sural nerve biopsy confirmed eosinophilic vasculitis, with fibrinoid necrosis and mononuclear infiltration around the vasa vasorum. Chest imaging revealed lower lobe consolidations and nodules, confirmed by HRCT.
The diagnosis of EGPA was established based on the constellation of bronchial asthma, peripheral eosinophilia, mononeuritis multiplex, p-ANCA positivity, and characteristic nerve biopsy findings. The patient was treated with pulse methylprednisolone followed by oral corticosteroids and cyclophosphamide. Neurological symptoms began to improve following immunosuppressive therapy.
This case underscores the importance of considering EGPA in patients with asthma who develop neurological symptoms, particularly mononeuritis multiplex. Early diagnosis using ACR/EULAR 2022 criteria and prompt initiation of immunosuppressive therapy can significantly reduce morbidity. The Five Factor Score (FFS) should guide treatment intensity, with cyclophosphamide recommended in patients with multi-organ involvement. This case highlights the role of detailed neurological assessment and tissue biopsy in establishing the diagnosis of EGPA, which may initially present with subtle yet disabling extrapulmonary features.
