Conclusion: EGPA is a rare systemic vasculitis with very limited cases reported in the pediatric population, while Mepolizumab, an anti-interleukin-5 monoclonal antibody, reduces blood eosinophil counts and improve refractory cases, which also allows dose reduction of high doses of systemic and inhaled steroids. The gene discussed is IL5; the disease is eosinophilic granulomatosis with polyangiitis.