chickenpox is a common childhood skin disease caused by a viral infection. the virus involved is called the varicella-zoster virus. today chickenpox is less common in the united states due to universal vaccination with the varicella virus vaccine though it still occurs in populations that are not routinely vaccinated. varicella-zoster virus is often categorized with the other common so-called "viral exanthems" (viral rashes) such as measles (rubeola) german measles (rubella) fifth disease (parvovirus b19) mumps virus and roseola (human herpesvirus 6) but these viruses are unrelated except for their tendency to cause rashes. in unimmunized populations most people contract chickenpox by age 15 the majority between ages 5 and 9 but all ages can contract it. chickenpox is usually more severe in adults and very young infants than children. winter and spring are the most common times of the year for chickenpox to occur.
what is chickenpox? what causes chickenpox?