ACUTE EOSINOPHILIC APPENDICITIS IN A CHILD WITH NORMAL TOTAL LEUKOCYTE COUNT AND ABSOLUTE EOSINOPHILIC COUNT

Abstract Introduction/Objective Eosinophilic appendicitis is a rare condition with a reported incidence of 0.03% to 1.2%, and often presents with clinical manifestations indistinguishable from acute appendicitis. Eosinophilic appendicitis may be associated with a localized allergic phenomenon. Methods/Case Report We present a 13-year-old male with ~24-hour history of constipation who was brought to the emergency department because of right lower quadrant abdominal pain, nausea, and vomiting. He was afebrile and had no antecedent of atopy or parasitic infestation. Laboratory investigation revealed an elevated C-reactive protein: 0.7 mg/dL [0.0-0.3]; mildly decreased hemoglobin: 12.2 g/dL [12.6 -16.8]; normal white blood cell count: 9.7 x10 3/mcL [3.2-10.6]; eosinophil count:1.7% [<5] and mildly elevated monocyte count: 0.9 x103/mcL [0.2-0.7]. Ultrasound examination revealed a non-compressible 7mm in diameter hyperemic appendix. The laparoscopic appendectomy specimen measured 9.5 cm long by 0.8 cm in diameter. The serosa was focally congested and there was mild mural thickening but no obvious sign of active appendicitis. Microscopic examination showed focally abundant mucosal eosinophils and a considerable sprinkling of eosinophils throughout the muscularis propria. No intraluminal parasite or neutrophilic associated mucosal damage was seen. The final diagnosis was: Acute Eosinophilic Appendicitis. Results (if a Case Study enter NA) N/A Conclusion Among the many and still intriguing causes of appendicitis is acute eosinophilic appendicitis. Eosinophils exert homeostatic roles in the normal host and pathological eosinophil-mediated processes over different tissues and their varied milieu. While this patient did not have any evidence of allergy, parasitic infestation, or elevated eosinophilic count in his work up, the presentation of acute appendicitis without an increase in total leukocytic count may alert for the possibility of an eosinophilic appendicitis. Conceivably, eosinophil mediators, such as IL-5, IL-33, granulocyte–macrophage colony-stimulating factor, thymic stromal lymphopoietin, and eotaxin-1 determine eosinophil behavior in a rarified appendix microenvironment.