# Herb-Induced Liver Injury by Laurus nobilis: A Case Assessed for Causality Using the Updated RUCAM

## TL;DR

A 55-year-old woman developed liver injury likely caused by consuming large amounts of Bay Laurel tea, highlighting the need to consider herbal products in liver disease diagnosis.

## Contribution

Demonstrates the hepatotoxic potential of Laurus nobilis using the updated RUCAM causality assessment.

## Key findings

- The patient's liver injury was scored as 'probable' herb-induced using the RUCAM scale.
- Liver function improved after discontinuing Bay Laurel tea consumption.
- Histopathology supported a diagnosis of toxic hepatitis.

## Abstract

Hepatocellular injury syndrome represents a pathological process with a broad etiological spectrum, including viral infections, autoimmune diseases, or intoxications. Clinicians must identify the potential cause using both anamnestic data and available paraclinical examinations. We present the case of a 55-year-old female patient, admitted to the Internal Medicine 1 Department at the Clinical County Emergency Hospital Bihor, Oradea, Romania. The patient exhibited nonspecific complaints and insignificant pathological antecedents, but from a biochemical perspective, substantial changes in liver transaminase levels were evident. To establish differential diagnoses, a series of biochemical and immunological tests were performed, along with a thorough medical history. It was concluded that the patient regularly consumes herbal infusions, specifically Laurus nobilis leaves, commonly known as Bay Laurel. Although this might be easily overlooked at first glance, a closer examination could explain the current clinical picture. In April 2024, a 55-year-old female patient with no history of liver pathology was admitted. She complained of asthenia fatigue, anorexia, mixed dyspeptic symptoms, diffuse abdominal pain, and a weight loss of 12 kg. The pathology had insidiously started approximately 3 months prior. On examination, the patient had altered general status, anorexia, and was overweight. Biochemically, the patient had elevated liver transaminase values (AST = 196 U/L and ALT = 357 U/L) that continued to rise during hospitalization, despite hepatoprotective treatment. Various paraclinical examinations were performed to exclude other potential causes of hepatic aggression, having excluded ordinary causes. Consequently, a liver biopsy was performed, and the histopathological examination leaned toward a toxic hepatitis etiology. Application of the updated RUCAM scale yielded a score of eight points (“probable” HILI—Herb-Induced Liver Injury). Clinical and biochemical improvement was observed after complete cessation of bay leaf tea consumption. This case highlights the potential hepatotoxicity of commonly used culinary herbs when consumed in large quantities or as concentrated infusions and emphasizes the importance of detailed anamnesis regarding herbal product use.