TY - JOUR AU - Taranish, Maha AU - Sehgal, Laveena AU - Zaid-Kaylani, Samer AU - Bhaskaran, Smitha PY - 2022/06/07 Y2 - 2024/03/28 TI - A Four-Year Old with Severe Idiopathic Hypereosinophilia JF - Journal of Rare Diseases and Orphan Drugs JA - jrdod VL - 3 IS - SE - Articles DO - 10.36013/jrdod.v3i.84 UR - https://spphllc.com/jrdod/article/view/84 SP - 1 - 5 AB - AbstractBackground:Background: Eosinophils are granulocytes that have a role in allergy and immune defense reactions. They represent a small percentage of circulating WBCs, and marked increases in their numbers can cause significant detrimental effects. Hypereosinophilia can be allergic, inflammatory, infectious, or malignant in origin. Hypereosinophilic syndrome is an uncommon disorder of eosinophils that can cause significant end-organ damage (Chen YY, Khoury P, Ware JM, et al.)Case presentation: A 4-year-old female presented with fever and abdominal pain and was found to have cervical and axillary lymphadenopathy spontaneously resolved and with an incidental finding of hypereosinophilia. The patient had an extensive workup, which was negative for common allergic, infectious, inflammatory, and neoplastic etiologies. She continued to show clinical and laboratory improvement and was discharged with the diagnosis of the idiopathic hypereosinophilic syndrome after the exclusion of other etiologies. Her follow-up after discharge showed improvement in eosinophil counts, and she is still being monitored. Given the lack of clear etiology and end-organ damage, she meets the definition of hypereosinophilia of undetermined significance. However, a gastroenterology workup is still considered as future symptoms evolve.Conclusion: Hypereosinophilia is a relatively uncommon disorder in the pediatric population that could be asymptomatic and discovered incidentally through laboratory workup; however, if it goes unrecognized, it can cause significant morbidity secondary to end-organ damage. Keywords: absolute eosinophil count, eosinophilia, hypereosinophilic syndrome.  ER -