Introduction: Resistance to antiviral therapy is getting actually more frequent. Immunocompromised host are more concerned with this problem.
Observation: We present a case of disseminated zoster resisting to acyclovir (ACV) therapy, but healing with foscarnet in a man treated with chemotherapy for lymphoma and seronegative for HIV. CI50 of VZV strain was 48 microM for ACV, which was 2.8 times higher than value of the reference OKA strain tested simultaneously, which confirmed the resistance for ACV.
Discussion: Immunocompromised patients often present varicella zoster virus (VZV) infection. They usually heal in response to ACV therapy, but some HIV infected patients have already presented with resistant strains of VZV. This case is the first described in a non-HIV infected patient. Foscarnet therapy resulted twice in complete healing because of its direct activity on viral DNA polymerase, so it is efficaceous therapy for patients with thymidine-kinase-deficient ACV-resistant VZV infection.