How to treat herpes zoster? Can it cause death?

Depends on situation. If you had chicken pox then you risk getting shingles. Vaccination the best way to lower the risk of getting shingles; the severity of pain and complications are signifantly decreased. Acyclovir is used for therapy, but is most effective witihn 48-72 hrs of an outbreak. Death from shingles is rare but can happen esp in pt with impaired immunity.
Shingles . Herpes zoster is due to flaring of dormant chicken pox infection along a verve , usually not lethal but will cause intractable pain even after healing for months ( years ) very little can be done , except symptomatic treatment.