Carambola Nephrotoxicity: Clinical Toxicology and Management

Abstract

Averrhoa carambola (Star fruit) is a commonly consumed tropical fruit in Southeast Asia and South America. Despite its nutritional benefits, several clinical and experimental studies have demonstrated its potential to cause severe nephrotoxicity and associated neurotoxic manifestations, particularly in individuals with impaired renal function. This article aims to review and synthesize updated evidence regarding the pathophysiology, clinical features, diagnosis, and management of carambola nephrotoxicity, along with practical preventive strategies for clinicians. Recent reports (within the past five years) indicate an increasing number of cases of acute kidney injury (AKI) following excessive or concentrated star fruit ingestion, both in healthy individuals and patients with chronic kidney disease (CKD). The primary mechanisms involve calcium oxalate crystal deposition within renal tubules and the accumulation of the neurotoxin caramboxin, leading to tubular obstruction, acute tubular necrosis, and neurological symptoms. Early recognition and early hemodialysis are key determinants for renal recovery and improve survival. This review highlights current clinical evidence, presents a representative case from Hua Hin Hospital and provides recommendations for early diagnosis, management, and public health prevention to reduce avoidable morbidity and mortality from star fruit toxicity, to increase awareness and reduce the incidence of preventable complication.