Varicella (chickenpox) is an acute infectious disease caused by varicella-zoster virus. It causes a blister-like rash, itching, tiredness, and fever. The rash starts off as red spots that typically develop into small fluid filled blisters (vesicles) that then crust over before healing. The rash usually appears on the head and then the trunk, followed by the arms or legs. Successive crops appear over several days. Adults and children with immunocompromising conditions are more likely to have severe disease and more complications.
Chickenpox hospitalised cases only are notifiable.