A Mysterious Case of Autoimmune Hepatitis Triggered by Herpes Zoster Virus Versus Drug-Induced Liver Injury

Autoimmune hepatitis triggered by Herpes Zoster infection is a relatively rare condition and a diagnosis of exclusion, as there are other more common causes of autoimmune hepatitis. While evaluating a patient with suspected autoimmune hepatitis, common causes such as viral hepatitis, Epstein-Barr virus, and medications like amoxicillin-clavulanic acid, statins, nitrofurantoin and methyldopa must be ruled out. Furthermore, autoimmune processes like thyroiditis, type 1 diabetes mellitus, rheumatoid arthritis, and ulcerative colitis should be considered. Herpes Zoster virus is known to cause diseases such as post-herpetic neuralgia, meningitis, meningoencephalitis, myelitis, cranial neuropathies, keratitis, uveitis, scleritis, and vision loss. Rarely, it can also trigger an autoimmune process in the body, causing hepatitis. A major dilemma that can be encountered while evaluating a patient with suspected autoimmune hepatitis precipitated by Herpes Zoster infection is drug-induced liver injury, especially if the patient had been managed with a medication known to cause liver injury. Both drug-induced liver injury and Herpes Zoster hepatitis have overlapping clinical, laboratory and histological pictures that can pose a significant diagnostic challenge. We report a case of autoimmune hepatitis in an elderly female precipitated by Herpes Zoster infection. She was observed with findings typical of cholestatic liver disease, and an extensive workup, including imaging and liver biopsy, was done to determine the cause of liver injury. Her clinical presentation, laboratory and Imaging findings favored Herpes Zoster virus as the likely culprit for autoimmune hepatitis.