Nannan Jiang Li Xiang ^* Huijie Huang ^* Xudong Zhang ^*

• Beijing Children’s Hospital, Capital Medical University, Beijing, China

Exercise-induced anaphylaxis (EIA) is a rare and potential life-threatening disorder. In difficult to control and refractory cases of EIA, biologics such as omalizumab and dupilumab have shown promise, with documented successful outcomes. Here, we present a case of EIA with lipid transfer protein (LTP) sensitization successfully treated with omalizumab with long-term follow-up. A 12year-old girl presented to our allergy department because of recurrent episodes of exercise induced anaphylaxis, with no specific food ingestion prior exercise. Allergen testing revealed sensitization to weed pollens, particularly mugwort (76.1 kUA/L) and Alternaria alternata (10.8 kUA/L).Allergen component testing indicated sensitization to LTP components from mugwort Art v 3 (49.9 kUA/L), wheat Tri a 14 (2.03 kUA/L) and peach Pru p 3 (11.5 kUA/L), with a negative result for omega-5 gliadin. Despite initial prophylactic treatment with Budesonide-Formoterol (80/4.5ug) and cetirizine 10mg to be taken before exercise, the patient still experienced EIA, and then she was recommended for dupilumab therapy (initial dose 600mg, followed by 300mg every 2 weeks for 6 doses). However, even while undergoing dupilumab therapy, she suffered two anaphylactic episodes after running 800-1000m. With the patient's consent, a trial of omalizumab was initiated. The patient was initiated on omalizumab injections of 300mg every 4 weeks. After two months omalizumab therapy, the patient showed significant improvement. She had been engaging in physical exercise three times a week and experienced a mild episode of urticaria.There were no further episodes of anaphylaxis or emergency room visits. By the fourth month of omalizumab treatment, she was able to consume food normally even just before exercising and had returned to her full activity level without any restrictions. This case presents the first successful off-label use of omalizumab in the prevention of EIA in the Chinese population. It is concluded that omalizumab may be helpful in resolving EIA symptoms as evidenced by this case of successful long-term use.