Chickenpox / Varicella
The most common cause of infection is through the respiratory droplets that are inhaled by another person. It is transmitted from person to person by droplet infection through the respiratory tract. People who have never had chickenpox can get infected just by being in a room with someone who has the disease. If one member in the family gets chickenpox, he usually will infect another family member unless precautions are taken.
Rarely the condition may be caused by exposure to herpes zoster.
The onset of the chicken pox rash may be preceded by a day of mild fever and weakness. The infectious period lasts from about three days before the rash appears until all the blisters have formed scabs.
Most children are infected with the virus by the age of 10. After infection, lifelong immunity against recurrent infection is usually present. People who have not had the disease are at risk of getting it; if they come in contact with an infected person. It affects all races and both sexes are equally prone to it.
Chicken pox is usually a self-limiting disease and symptoms usually go away without treatment. However in some patients severe complications may occur. It may precipitate herpes zoster, hemorrhages, pneumonia, brain disorders, etc.
Vaccination against chicken pox is available in some countries.