Role of bacterial superinfections in the pathogenesis of postzosteric neuralgia.
Varicella-zoster virus (VZV) is an alpha-herpes virus that causes varicella (chickenpox), establishes latency in dorsal root ganglia and may reactivate to cause herpes zoster (shingles). Postherpetic neuralgia is the most common debilitating complication of herpes zoster. It is currently supposed that scarring of the dorsal root ganglia and atrophy of the dorsal horn as a result of intense inflammation may play a central role in the pathogenesis of this condition. The exact pathogenesis of the inflammatory reaction leading to persistent ganglion damage is still poorly understood. However, immune suppression is a recognized risk factor for the development of postzosteric neuralgia in zoster patients (increased risk, e.g., in aged patients over 80 years or diabetes mellitus patients). There is some evidence that remote streptococcal and staphylococcal infections may induce immunologic disease mechanisms consequently affecting the central nervous system. Since streptococcal and/or staphylococcal superinfection of skin lesions is common in herpes zoster, we present a hypothesis of immunopathogenesis of postzosteric neuralgia, i.e., as the result of augmentation of local ganglion inflammation due to bacteria-driven clonal expansion of VZV-specific T-cell subsets in the affected skin. Based on the aforementioned hypothesis it is interesting: (1) to study the impact of concomitant systemic antibiotic treatment to the standard antiviral regimen on the rate and severity of both bacterial superinfection of zoster skin lesions and postzosteric neuralgia and (2) to quantify the VZV-specific T-cell response as a function of the degree of bacterial superinfection of zoster skin lesions. Challenging of the present hypothesis should provide an effective means of preventing postherpetic neuralgia by preventing and consequently treating the bacterial superinfection of zoster skin lesions.
Bassukas
Ioannis D
ID
Department of Skin and Venereal Diseases, University Hospital of Ioannina, University of Ioannina, Medical School, S. Niarhos Avenue, 45500 Ioannina, Greece. ibassuka@cc.uoi.gr
Kiorpelidou
Despoina
D
D014645:Herpesvirus 3, Human / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D051474:Neuralgia, Postherpetic / Q000150:complications / Q000209:etiology*; D015163:Superinfection