Fatal Chronic Varicella‐Zoster Viral Infection in a Young Man With Chediak–Higashi Syndrome

Chediak–Higashi syndrome ( CHS ) is a rare autosomal recessive primary immunodeficiency characterized by partial oculocutaneous albinism, neurologic involvement, and a predisposition to severe infections. Patients are particularly susceptible to developing hemophagocytic lymphohistiocytosis ( HLH ), which significantly worsens prognosis. We report the case of a 19‐year‐old male with CHS , under long‐term immunosuppressive therapy for chronic HLH , who developed chronic VZV infection. Despite treatment with valacyclovir, the lesions progressed, and virological investigations confirmed the diagnosis of acyclovir‐resistant varicella‐zoster virus ( VZV ). The clinical course was marked by the appearance of neurological symptoms and a fatal outcome. To our knowledge, this is the first reported fatal case of chronic VZV infection with systemic dissemination in a patient with CHS . This case highlights the risk of resistance associated with long‐term prophylaxis and the complexity of managing herpesvirus infections in immunocompromised patients receiving JAK inhibitors.