Chicken-pox is an infecto-contagious condition caused by the virus called varicella-zona zoster that is also responsible for the apparition of shingles or herpes. Cases of chicken-pox are more and more rare now as all children receive a vaccine against the virus. The incubation period for the condition is usually from 10-21 days after a child has been infected by coming in contact with another case of chicken-pox or with a child suffering from herpes zoster.

The prodromes of the viral infection include low-grade fever, headaches, weakness, loss of appetite and low intensity abdominal pains within the first 3-4 days after catching the infection. The actual rash specific for chicken-pox primarily develop on the patient's scalp, trunk and face and appear as small red spots on the skin, very itchy as well. In a few days they turn into larger vesicles filled with fluid, become umbilicated and eventually crust over.

The fever in this viral infection usually lasts for about 4 days while new vesicles appear on the child's trunk, arms and legs. In 6-7 days after the illness has manifested, all lesions are already crusted over. In the next week all crusts fall off without leaving any scars on the skin; it may take up to 20 days before the crusts fall off. As the implicated virus is known to be also responsible for causing herpes and zona-zoster, some of the pediatric patients may develop ulcers inside their mouth cavity.

Beside the classical symptoms due to chicken-pox, some further signs may occur if the condition has developed complications. A red area may occur around the vesicles, breathing difficulties and coughing are also possible and vomiting is possible as well. In severe cases, neurological symptoms respond by headaches, seizures, slurred speech and walking problems.

A usual case of chicken-pox will lead to the appearance of about 300 skin lesions on the child's body. The viral lesions of the skin can sometimes appear in different stages at the same time; flat red spots, vesicles with fluid and crusted vesicles can be present in the same time. Fever in average chicken-pox cases rises up to 100-102 degrees Fahrenheit, but in more severe cases it can reach also 106 degrees.

Children who have caught the virus are already contagious 1-2 days before the actual symptoms develop. The contagiousness persists until all the crusted vesicles disappear from the skin surface. Of main importance is keeping the child from scratching as all scratched crusts may lead to permanent scars. If the child has been vaccinated against the virus, the condition is most likely atypical with mild symptoms and less skin lesions.