Satellite lesions accompanying herpes zoster: a new prognostic sign for high-risk zoster.

ABSTRACT

BACKGROUND: The incidence, clinical relevance and pathogenesis of single, isolated, varicella-like skin lesions occurring far beyond the primary herpes zoster (HZ)-affected dermatome remain unclear. OBJECTIVES: To search prospectively for these satellite lesions in 120 patients with HZ and to correlate their presence with a series of clinical, histological and virological data. METHODS: Relevant clinical data were recorded from 109 patients with proven HZ using immunohistochemistry on Tzanck smears. Furthermore, skin biopsies and blood samples were obtained from a subgroup of patients presenting with primary HZ with and without satellite lesions for histology, immunohistology, serology and real-time polymerase chain reaction. RESULTS: This study identified satellite lesions in 21·1% of the patients with HZ. Their presence conveyed a statistically significant relative risk (RR) for severe (RR 3·27, P < 0·001), multidermatomal (RR 10·6, P < 0·001) and multistage HZ (RR 3·30, P < 0·001); systemic signs (RR 2·08, P = 0·0031); immunosuppression (RR 2·38, P = 0·0014) and hospitalization (RR 2·94, P < 0·001). Varicella zoster virus (VZV) viraemia was higher (mean 4075 copies mL(-1) ) in patients with HZ with satellite lesions than in those without (mean 1466 copies mL(-1) ). In contrast to HZ lesions, satellite lesions often presented positive VZV immunostaining in endothelial cells, suggesting a similar pathogenesis to varicella. A limitation of this study is the centre-linked overrepresentation of immunocompromised patients. CONCLUSIONS: Total-body examination searching for satellite lesions is a rapid, simple and reliable tool for identifying patients with high-risk HZ.