label: herpes zoster
label_lc: herpes zoster
description: A common dermal and neurologic disorder caused by reactivation of the varicella-zoster virus that has remained dormant within dorsal root ganglia, often for decades, after the patient's initial exposure to the virus in the form of varicella (chickenpox). It is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area.