Cutaneous Herpes Zoster Infection as a Rare Etiology of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH): A Case Report

Herpes zoster is caused by a reactivation of the varicella-zoster virus after primary manifestation during childhood as chicken pox, commonly occurring in elderly and immunosuppressed patients. Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) is defined by the unsuppressed release of antidiuretic hormone (ADH) from the pituitary gland, with impaired water excretion causing hyponatremia. Though limited, literature supports herpes zoster infection inducing SIADH, through a proposed mechanism of alteration of the ADH regulator pathway due to viral infection of the dorsal root ganglion (DRG). Our case is distinct in that our patient presented elements of hypovolemic hyponatremia with concomitant SIADH.