Transient Eosinophilic Granulomatosis with Polyangiitis-Like Vasculitis During Omalizumab Therapy: A Case Report.

A 67-year-old Caucasian female presented in August 2019 to our rheumatology service, with 3 days history of severe neck pain and right-sided headache with aches in both shoulders and arms and mild stiffness. Other symptoms included mild jaw claudication. She had recently returned from Majorca after an uneventful two-week trip. She had a background of severe allergic asthma and allergic rhinitis, well controlled with omalizumab which was started in 2016, based on persistently high IgE. Her sister suffers from a type of vasculitis and is currently on steroids. The patient is an ex-smoker and drinks two bottles of wine a week. She had high inflammatory markers with raised eosinophilic count and was admitted for further work up to rule out infection and to commence steroid after for a likely diagnosis of eosinophilic granulomatosis with polyangiitis. Shortly after admission to the acute assessment unit, she became confused and febrile. An extensive work up ruled out infection, and she was started on steroids and treated for acute hyponatremia. Omalizumab was stopped. She improved and was discharged on a tapering dose of steroids and was weaned off completely within 4 months. Her inflammatory markers returned to normal as well as her eosinophilic count, with complete resolution of her presenting symptoms.