There is no seasonal pattern for herpes zoster. The likelihood of infection is related to both age and immune status. The incidence of disease in patients older than 60 years is two to three times higher than that in younger individuals. After local replication of VZV at the site of virus entry, the virus is carried via blood leukocytes to focal skin areas and visceral organs. Illness usually presents with a generalized vesicular eruption that is followed by a variable prodrome of headache, fever, and malaise.
Vesicles often appear initially on the face or trunk.
The vast majority of childhood cases are uncomplicated and resolve in seven to 10 days without producing scarring. In adolescents and adults, pneumonia may develop that is characterized by cough, tachypnea, and diffuse reticulonodular infiltrates, which may calcify with time. Pulmonary diffusion difficulties may persist for a period of weeks to months. Disseminated disease is more likely to develop after varicella infection in children with leukemia, lymphoma, or Hodgkin's disease. It is believed that after an initial episode of varicella, the virus persists in sensory ganglia in a quiescent state, which has yet to be fully defined.