Myiasis is defined as infestation of a mammal by fly larvae. It may occur on either living tissues (primary myiasis) or dead tissues (secondary myiasis). In this report, we present a patient with myiasis with an extremely rare clinical manifestation and severe allergic reaction, and we review the literature in order to reveal the current status. A 20-year-old female patient was admitted to our emergency department due to rush on face, cough and shortness of breath. The maggot came out of her nose was identified as Oestrus ovis. With a diagnosis of severe allergic reaction due to myiasis, she was treated diphenhidramine, prednisone and inhale albuterol in the emergency department. After treatment and further investigation, she was discharged with full recovery. Myiasis is a rare cause for severe allergic reaction in patients with definite diagnosis. Immediate diagnosis and treatment are milestones in preventing bad outcomes.