CAUSES Varicella (Chickenpox) is a childhood infectious disease survived by almost every child. Chickenpox is caused by the varicella-zoster virus. It is characterized by itching and rash (small bubbles filled with fluid) of skin. A day or two before rash appears a person may have fever and feel exhausted. Rashes start with few small red spots that soon become filled with fluid (they look like small bubbles). During the next 2-4 days, bubbles appear in groups, first on body, later on arms, legs and face. Rashes can even appear in the mouth and on other inner parts of body. The bubbles burst and turn into light brown crust that later become darker and fall off at the end (usually 2 weeks from first symptoms). The bubbles can get infected when scratching, most often with staphylococcus bacteria.

SPREAD Chickenpox is spread from one person to another by direct contact or through the air from an infected person's coughing or sneezing. Touching the fluid from a chickenpox bubble can also spread the disease. Person infected with chickenpox can be contagious two days before rash appears and six days after the first bubble appears or until all bubbles turn into crusts. Incubation is 10 – 21 days. Most children get chickenpox till the age of 10. When recovered once , the person usually gets lifetime immunity.

PREVENTION The patient should be isolated till the last bubble disappears. It usually lasts for 5-6 days from the first sign of the disease. There are 2 types of immunization: active and passive. Passive immunization – a vaccine that contains Chickenpox virus antibodies. Usually , this vaccine is given to pregnant women and infants exposed to mothers' chickenpox virus. By passive immunization, disease can be prevented or at least considerably attenuated. Active immunization-a vaccine that contains alive attenuated chickenpox virus. This vaccine is obtained in many countries. In US it is recommended during second year. In Croatia it is still not part of obligatory vaccination calendar.

TREATMENT Chickenpox is one of rare virus infections that can be treated by a drug – acyclovir, but taking this drug can only be recommended by doctor. Uncomplicated forms of disease are not treated by drug, usually disease is treated only by resting, controlling body temperature, maintaining body hygiene (to prevent secondary skin infections), bathing in hypermangan solution etc.