What is Chicken Pox?

What is Chicken Pox?

What is Chicken Pox?

IMPORTANT NOTE: Corvelva invites you to get in-depth information by reading all the sections and links, as well as the manufacturer's product leaflets and technical data sheets, and to speak with one or more trusted professionals before deciding to vaccinate yourself or your child. This information is for informational purposes only and is not intended as medical advice.

Chickenpox is a disease caused by the varicella zoster virus, a DNA virus that belongs to the herpes virus family (Alphaherpesvirinae) and is associated with shingles. The virus initially presents as a chickenpox infection; however, because the virus is able to remain in the sensory nerve ganglia of the body after the first infection, it has the potential to become reactivated. If the virus reactivates, it looks like a shingles infection.(1) The chickenpox virus is found only in humans, and outbreaks usually occur between March and May in the United States.(2)

Chickenpox is transmitted through direct contact with chickenpox blisters, inhalation of particles from chickenpox blisters, and possibly contact with virus-infected respiratory secretions.(3) Chickenpox symptoms generally begin between 10 and 21 days after exposure to the virus, and the illness typically lasts between 5 and 10 days. In adults, early chickenpox symptoms can include headache, fever, loss of appetite, and fatigue. These symptoms usually start 1 to 2 days before the rash appears; however, in children, the rash is often the first sign of infection.(4)

When chickenpox rash occurs, it usually starts with raised, itchy red or pink bumps (papules). These bumps usually last for a few days before turning into fluid-filled blisters (vesicles). After about a day, the blisters open, ooze, and eventually scabs and scabs form.(5) The rash usually starts on the head, then spreads to the trunk and finally to the arms and legs. The rash may also be present in the eyes, throat and genitals.(6) Since the rash appears over several days, chickenpox lesions can be present on the body in the form of papules, vesicles and crusts at the same time. On average, healthy children have between 200 and 500 chickenpox lesions, which are typically 1 to 4 millimeters in diameter.(7)

Chickenpox infections can occur in vaccinated people, but it is often a milder infection, with fewer than 50 skin lesions, and the rash often appears as papules rather than blisters. Fever rates may also be lower among vaccinated individuals who develop chickenpox. 25-30% of people who develop chickenpox after receiving a dose of chickenpox vaccine may still experience a disease similar to a natural chickenpox infection. Information about the presentation of chickenpox disease among people vaccinated with two doses of the vaccine is currently limited.8 A person with chickenpox chickenpox is still contagious and can spread the disease to others.(9)

A person with worsening chickenpox with fewer than 50 lesions is thought to be two-thirds less likely to transmit the disease than someone who has developed more than 50 lesions; however, the mild clinical presentation may delay the diagnosis. As a result, individuals with undiagnosed chickenpox have the potential to cause higher transmission rates within the community, by not taking isolation precautions to prevent spreading the disease to others.(10)

Chickenpox is considered a mild infection; however, complications can occur. Complications of chickenpox can include viral and bacterial pneumonia, bacterial skin infections, encephalitis, cerebellar ataxia, septicemia, necrotizing fasciitis, toxic shock syndrome, osteomyelitis, and septic arthritis.(11) Infants born to mothers infected with chickenpox between 5 days before and 2 days after delivery, premature infants, pregnant women, and people with immunosuppressed conditions are considered to be at higher risk of developing complications.(12)

Before the introduction of the chickenpox vaccine, nearly everyone developed the infection as a child. About 4 million cases of chicken pox occurred in the United States each year, with most cases affecting children younger than 15 years of age. Children aged 1 to 4 had the highest rates of chickenpox infections, closely followed by children aged 5 to 9. Only 7% of chickenpox infections occurred in adults.(13) Chickenpox was removed from the National Complaint List in 1981, but returned to the list in 2003.(14) Chickenpox-related deaths have been subject to national reporting since 1999(15) and in 2017, 2 chickenpox-associated deaths were reported in the United States.(16)

Recovery from chickenpox confers long-lasting natural immunity, and immunocompetent individuals rarely experience a second attack.(17) Re-exposure to the chickenpox virus strengthens a person's immune system and decreases the risk of shingles infection.(18)

This article is summarized and translated by National Vaccine Information Center.



Publish the Menu module to "offcanvas" position. Here you can publish other modules as well.
Learn more.