The virus varicella-zoster is known to produce more infecto-contagious conditions such as chicken-pox, shingles and herpes. The incubation period for the virus varies from 10 to 21 days before the actual characteristic rash appears. The main symptoms of the infection are fever, headaches, swollen lymph nodes and general weakness.

The rash appears on a red surface with small red bumps turning into blisters n a few hours. The rash is most common to occur on the patient's face and trunk and the number of lesions is variable from person to person. Initially, blisters are filled with infection fluid and become cloudy in about 4 days when the crust over and dry out. The lesions are generally very itchy and take about7-10 days to scrub; if no scratching is performed by the patient, the bumps cure without scarring. Chicken-pox rash occurs frequently once in a lifetime but second infections with milder symptoms are also possible.

Shingles are more commonly encountered in adults and evolve in usually two major stages. The first stage is the one of prodromes with warning symptoms, the second one evolves with the signs of the actual infection and a third stage is possible showing postherpetic neuralgias. The shingles affecting the course of a nerve are known as zona-zoster and begin with initial pain without the rash that occurs later.

Shingles is the reinfectional form of the condition and often evolves with muscle aches, sharp aching pains and itchy sensitive to touch skin. The prodromes with pain usually precede the rash with about1-5 days. The most common locations of the rash is trunk, face, neck and lower back; if located on the face, the rash is dangerous as it can affect the mouth and provoke injuries to the eye cornea.

The active infection is accompanied with pain and goes from small red bumps to blisters filled with infection fluid and lesions filled with pus. In usual cases the blisters crust and heal in about 7-10 days but the infection can last up to months in case of an impaired immune system.

Another more unusual form of the viral infection is zoster sine herpete, more seen in elder subjects and evolving with fever, burning pain, headaches, chills and nausea. The postherpetic neuralgia persists about a month after the onset of the infection and occurs in about 10-20% of the infected patients. The risk of the virus reoccurring is low as the immune system develops antibodies after the first infection.