Hutchinson's sign associated with herpes zoster indicates reactivation of which cranial nerve?

Hutchinson's sign is significant in the context of herpes zoster, particularly in cases affecting the ophthalmic division of the trigeminal nerve. This sign refers to the presence of herpes zoster lesions on the tip of the nose, indicating potential involvement of the cornea and a higher risk for ocular complications. It suggests that the reactivation of the herpes zoster virus is linked to the nasociliary branch of the trigeminal nerve.

The nasociliary branch is crucial as it provides sensory innervation to the cornea and the surrounding structures. When herpes zoster affects this branch, it can lead to serious ocular sequelae, including keratitis and other corneal pathologies. Therefore, the presence of Hutchinson's sign is a clinical alert for possible ocular involvement and underscores the need for ophthalmic evaluation and intervention.

Understanding this relationship helps clinicians recognize the implications of zoster reactivation and the management required for patients showing signs indicative of these infections.