Chronic verrucous varicella tester virus skin lesions: clinical, histological, molecular and therapeutic aspects

The outbreak of HIV infection introduced a new phenomenon in varicella test er virus (VZV) pathology namely the long-standing wart-like skin lesions th at are frequently associated with resistance to thymidine kinase (TK)-depen dent antiviral agents. This paper reviews the clinical, histological, and m olecular aspects and the therapeutic management of these verrucous lesions. The majority of lesions are characterized by chronically evolving, unique or multiple wart-like cutaneous lesions. The main histopathological feature s include hyperkeratosis, verruciform acanthosis and VZV-induced cytopathic changes with scant or absent cytolysis of infected keratinocytes. The mech anism that establishes the chronic nature of the lesions appears to be asso ciated with a particular pattern of VZV gene expression exhibiting reduced or nondetectable gE and gB synthesis. Drug resistance to TK-dependent antiv iral agents is a result of nonfunctional or deficient viral TK. This necess itates alternative therapeutic management using antiviral agents that targe t the viral DNA polymerase.