Occasionally, the lesions may be bullous or hemorrhagic. Residual scarring is exceptional. Constitutional symptoms tend to be mild even in the presence of extensive exanthem. The most common complication is secondary infection of the skin lesions, usually caused by streptococci or staphylococci. These skin infections may lead to severe sequelae.
Septicemia can occur.
CNS complications, which are uncommon, include encephalitis, cerebellar ataxia, aseptic meningitis, and myelitis. Glomeruonephritis, myocarditis, and arthritis have also been reported. Chickenpox in Immunocompromised Children Varicella may be severe and even fatal in children with underlying malignancy, those with congenital defecits in cellular immunity, or in those receiving high doses corticosteroids. These children, who have a mortality rate approaching 10 per cent, may develop what has been termed as progressive varicella. Instead of developing new vesicular lesions for several days, they continue to have fever and new lesions for as long as 2 weeks after the onset of illness.