Mononeuritis Multiplex As the Initial Presentation of Eosinophilic Granulomatosis With Polyangiitis (EGPA) in a Non-asthmatic Filipino Female: A Case Report

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare disease characterized by necrotizing vasculitis of small and medium-sized systemic blood vessels. The three phases to this disease are: 1) prodromal phase, which includes asthma, 2) eosinophilic phase, and 3) vasculitic phase. There is currently no diagnostic criterion for the diagnosis of EGPA, and diagnosis relies more on clinical features. On laboratory testing, peripheral eosinophilia is a hallmark of diagnosis. Treatment for new-onset antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis with organ or life-threatening disease includes a combination of rituximab with glucocorticoids. This paper presents the case of a 40-year-old non-asthmatic female from the Philippines who initially presented with subacute progressive asymmetric bilateral leg pain with distal weakness and numbness. Blood tests for complete blood count, antineutrophil cytoplasmic antibodies, and inflammatory markers were done along with nerve conduction studies. Diagnostics revealed eosinophilia, perinuclear anti-neutrophil cytoplasmic antibodies positivity, and mononeuritis multiplex, which led to the diagnosis of EGPA. She was treated with steroids and rituximab. A follow-up after one year of treatment showed marked improvement of neurologic status and functional outcome. Muscle strength and sensation had improved, and the patient was eventually able to ambulate with minimal assistance and work on a computer job. This case reports atypical presentation of EGPA, initially presenting as malaise and sensorimotor disturbances with gradual progression of symptoms in four weeks with no history of severe asthma or any respiratory symptoms.