Starfruit-Induced Neurotoxicity Masked by Multiple Medical Confounders in a Hemodialysis Patient

Starfruit (Averrhoa carambola) contains a potent neurotoxin, caramboxin, which can induce severe and often fatal encephalopathy in patients with impaired renal function. The diagnosis is frequently challenging due to nonspecific initial symptoms that can mimic other common complications in the end-stage renal disease (ESRD) population. A 63-year-old female patient with ESRD on maintenance hemodialysis presented with intractable hiccups, emesis, and chest pain. Her hospital course was immediately complicated by a hypertensive emergency and an elevated troponin level. Other labs were significant for hyperkalemia (potassium 5.7 mEq/L) and high-anion-gap metabolic acidosis. Following a hemodialysis session, she developed a severe, fluctuating encephalopathy. In view of a sudden decline in mental status, the patient underwent a CT head and an MRI head, which were negative for acute findings. The diagnostic workup was confounded by multiple concurrent issues, including lumbar puncture results suggesting meningitis, seizure-like activity requiring antiepileptic drugs, and an electroencephalogram (EEG) suggestive of toxic-metabolic encephalopathy. Furthermore, the patient developed new-onset atrial fibrillation. On the fifth day of admission, a detailed over-the-counter and dietary history obtained from the family revealed a significant starfruit ingestion two days prior to symptom onset. With the diagnosis of starfruit intoxication established, management was refocused on intensive hemodialysis. The patient's mental status gradually improved with increased frequency of renal replacement therapy as the toxin was cleared and confounding medications were withdrawn. This case illustrates how the classic presentation of starfruit neurotoxicity can be obscured by a complex clinical picture. It underscores that a high index of suspicion and a persistent, detailed dietary history are critical for a timely diagnosis and management of unexplained encephalopathy in all ESRD patients.