2483 Amoxicillin-Induced Eosinophilia in Portal Tracts—A Rare Case of Idiosyncratic Acute Cholestatic Hepatitis

Abstract

INTRODUCTION: Drug induced liver injury (DILI) accounts for approximately 10 percent of all cases of acute hepatitis. Amoxicillin/clavulanic acid induced liver injury is a well-recognized complication but amoxicillin alone has rarely been linked with clinically significant idiosyncratic liver injury. It is exceedingly uncommon to see eosinophilic penetration of portal tracts with amoxicillin induced liver injury. CASE DESCRIPTION/METHODS: A 21 year old obese woman presented with jaundice preceded by fever and right upper quadrant abdominal pain for 1 week. She had completed a 10 day course of amoxicillin for an ear infection 3 weeks back. She denied any alcohol, acetaminophen, herbal medications, recent travels or exposure to sick contacts. She had scleral icterus and tender hepatomegaly with no rash on exam. Serum AST, ALT and ALP were moderately elevated with peaks of 216 U/L, 296 U/L and 466 U/L respectively. Serum bilirubin peaked at 13.1 mg/dL with direct component of 9.7 mg/dL. Blood differential count was significant for elevated eosinophils 0.8 k/uL (range 0.1-0.3 k/uL). Work up was negative for viral and autoimmune hepatitis. The levels of ceruloplasmin, alpha-1-antitrypsin and immunoglobulins were normal. Ultrasound and MRCP showed an enlarged fatty liver with no evidence of biliary ductal dilatation. Liver biopsy showed expanded portal tracts with marked inflammatory infiltrate composed predominantly of neutrophils with many eosinophils, and scattered lymphocytes and plasma cells. There was hepatocellular and canalicular cholestasis with no bile ductular reaction. DISCUSSION: The incidence of DILI with amoxicillin alone is 0.3 per 10,000 prescriptions compared to 1.7 per 10,000 prescriptions with amoxicillin/clavulanic acid. Risk factors are older age, female sex, pregnancy, high BMI and excessive alcohol intake. Signs and symptoms begin within 6 weeks of initiating amoxicillin, including nausea, abdominal pain, jaundice, fever, pale stools, dark urine, and pruritus. The mechanism of amoxicillin hepatotoxicity is unknown with possibility of idiosyncratic immune allergic reaction. Histologically liver injury appears most often as a cholestatic hepatitis and may have associated bile duct injury manifesting as extensive infiltration of the biliary epithelium with inflammatory cells accompanied by nuclear irregularity, cytoplasmic vacuolization and eosinophilia of the biliary epithelium. The primary treatment is the withdrawal of the drug.