Immune reconstitution is the trigger of herpes zoster with lymphopenia and high neutrophil-to-lymphocyte ratio (NLR) in a retrospective cohort study.

HZ develops in a state of immune reconstitution with immunocompromised conditions, as part of the unmasking immune reconstitution inflammatory syndrome (IRIS). Lymphopenia prior to HZ onset is one of the most crucial factors in its pathogenesis and vital prognosis.