Varicella is caused by varicella zoster virus (VZV). VZV causes 2 clinically distinct forms of disease: varicella (aka chickenpox) and herpes zoster (aka shingles). The incidence of varicella has decreased dramatically since the introduction of the varicella vaccine in 1995. Patients typically have multiple vesicular lesions at different stages at the same time.Source: Brown Skin Matters
Treatment depends on the patient’s age! Supportive care is usually all that is necessary in patients <12yo because the disease is typically self-limited. Antiviral therapy (e.g. acyclovir or valacyclovir) should be considered in patients at increased risk of complications.