Zoster（带状疱疹）ppt课件.ppt

Herpes Zoster ;Papule;; Skin lesions just like letters.?Without them,?we?will not be able to?read?the literature?of skin. ——Dr. Darier;How to describe this lesion ?;Herpes Zoster ; Definition Herpes zoster is caused by Varicella - Zoster virus (VZV) , classically occurs unilaterally within the distribution of a sensory nerve, being characterized by clustered vesicles and considerable neuralgia. ;Pathogen and Pathogenesis ;Pathogen Varicella-Zoster virus (VZV) is characterized by neurotropism and dermatotropism. It soon lose activity in the dry environment.;Pathogenesis VZV causes varicella in childhood , and establishes latency in sensory ganglia after the primary infection. VZV may replicate later in life, taking advantage of the decline in immune function, traveling down the sensory nerve into the skin.;Pathogenesis ; The incidence of herpes zoster increases with advancing age and decline in immune function. ;Clinical manifestations;Prodrome: headache and fever hyperaesthesia pain;Features of lesions The eruption initially presents as papules and plaques of erythema in the dermatome. Over a few days, crops of clustered red papules form in a discontinuous band and quickly evolve to clear vesicles.;Typical features of lesions ; Lesions may become hemorrhagic, necrotic, or bullous.; The vesicles slowly become pustulars, and rupture to form crusts , which separate in 2 to 4 weeks, often with scales. ; The total duration of the eruption depends on three factors: patient age; severity of eruption ; presence of underlying immunosuppression.;Distribution cranial or spinal sensory nerve.