What Causes Chickenpox?

Chickenpox is a contagious condition triggered by exposure to the varicella-zoster virus (VZV), which also causes shingles in adulthood. A member of the herpes family of viruses, the presence of the chickenpox pathogen normally causes illness in children, but may present severely and trigger the development of complications in adults and individuals with certain medical conditions who never had chickenpox when they were young. In most cases, treatment for the VZV that causes chickenpox allows for the virus to run its course with little to no interference other than the possible administration of an antihistamine to alleviate inflammation and discomfort. Individuals with a history of the VZV that causes chickenpox are considered to be in the precarious position of possibly developing shingles later in life since the varicella-zoster virus is a lifelong condition that remains dormant in one’s system.

Varicella-zoster virus is a form of herpes that is transmitted through the air and causes chickenpox in individuals who do not possess immunity to the bacterial pathogen. As an individual ages, the presentation of this virus can adopt a more serious manifestation triggering complications. Once exposed, the VZV remains dormant in the individual’s system for the rest of his or her life. In later years, the virus may re-manifest in the form of a painful, yet benign condition known as shingles.

A diagnosis of chickenpox is made by a visual examination of the tell-tale blistery rash with which it presents. Under normal circumstances, the illness is mild in its presentation and often takes several days to run its course. Infants and adults are considered at a greater risk for developing more severe presentations of the illness due to compromised immunity or the presence of existing infection. To prevent the spread of infection, individuals are advised to avoid interpersonal contact and social situations, such as work or school, until all blisters have dried and scabbed over.

Individuals with a mild presentation of the VZV that causes chickenpox initially present with a rash that may appear as widespread bites that are irritated and itchy. As the virus progresses, the irritated lesions will fill with clear liquid to form a blister before rupturing and scabbing over. The progression of blister formation may vary by individual. Additional signs that often accompany rash development include fever, malaise, and headache. It is important to refrain from scratching the blisters to prevent the development of a secondary infection and scarring once the blisters have healed.

Complications associated with the VZV that causes chickenpox are rare in their occurrence. Those who possess compromised immunity, certain existing medical conditions, or women who are pregnant are considered to be at an increased risk for complication development, including acquiring more severe bacterial infections such as pneumonia and encephalitis. The most common complication of chickenpox is the manifestation of a bacterial-based, dermal infection that may occur in the presence of scratching.

Pregnant women who present with the VZV that causes chickenpox possess the ability to pass the infection on to their fetus. The passage of infection and severity of its presentation are entirely dependent on the timing of the illness; latter presentations possess a greater chance for complication development. In addition to congenital infection, additional complications may include physical deformity and low birth weight.