TY - CHAP M1 - Book, Section TI - Eosinophilic Diseases A1 - Ujiie, Hideyuki A1 - Shimizu, Hiroshi A2 - Kang, Sewon A2 - Amagai, Masayuki A2 - Bruckner, Anna L. A2 - Enk, Alexander H. A2 - Margolis, David J. A2 - McMichael, Amy J. A2 - Orringer, Jeffrey S. PY - 2019 T2 - Fitzpatrick's Dermatology, 9e AB - AT-A-GLANCEEosinophils are bone marrow–derived cells that circulate transiently and normally account for up to 6% (up to 600/mm3) of circulating blood leukocytes.Eosinophils primarily are tissue-dwelling cells, but only in certain tissues in humans, with an average tissue life span of 2 to 5 days that may be increased with eosinophil survival factors for up to 14 days.As proinflammatory cells, the presence of eosinophils within most tissues is associated with pathologic states that include infections, allergic reactions and atopic diseases, fibrotic disorders, reactive eosinophilias, and hypereosinophilic syndromes.Eosinophils play a role in innate and adaptive immune responses, which may explain why they are present in normal, noninflamed tissues such as the gastrointestinal tract and lymphoid tissues.This section reviews the biologic actions of eosinophils with particular focus on what controls eosinophil production, activation, and tissue trafficking.Pharmacologic manipulation of eosinophil inflammation is possible as new, more specific strategies are emerging. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/10/11 UR - dermatology.mhmedical.com/content.aspx?aid=1161329698 ER -