VPMD: Chickenpox (VZV)

What is VZV?

Varicella- Zoster virus (VZV) is a virus known to cause chickenpox and shingles. Chickenpox is a highly contagious infectious disease that is associated with a characteristic itchy rash. Following the primary infection with VZV, the virus may remain inactive within the nervous system for years before reactivating to cause shingles. Shingles is an infectious disease manifested by a painful rash that characteristically affects one side of the body. In both cases the virus can be spread by contact with respiratory droplets and direct contact with the fluid from the rash. Chickenpox can affect persons of all ages but severe infection is common in infants, adolescents, adults, pregnant women and immunocompromised.

What are the symptoms of chickenpox?

Chickenpox may present with a fever, fatigue , +/- sore throat followed by the development of an itchy blister rash. The rash usually evolves from bump to blister to scab over a weeks time with different crops of rashes presenting at different stages. This infection may be complicated by pneumonia ,encephalitis and bacterial soft tissue infections. Infected persons remain contagious until the rash is scabbed over, which usually occurs in about 1-2 weeks. Scabs fall off within 2 weeks.

How is Chickenpox diagnosed?

Chicken pox is largely diagnosed based on clinical presentation but demonstration of viral genetic material via PCR testing from a rash sample, confirms infection.

How is Chickenpox treated?

In children, the focus of treatment is on symptoms; topical and at times, oral medications aimed at controlling itchiness is the focus of therapy. Fever control is also aided with acetaminophen/ibuprofen. In those at risk for severe disease, antivirals are available.

How is chickenpox prevented?

Since its introduction in the mid 90s within the US, the VZV vaccine has had a significant impact on the incidence of chickenpox. The vaccine is a two dose series, with the initial dose given 12-15 months and the second dose usually given at 4 years old.

In those whom have been exposed to a close contact with chickenpox, they may receive the vaccine if older than 12 months or VZV immunoglobulin if too young for the vaccine or it is otherwise contraindicated.

Of note, those whom have been vaccinated may still contract varicella but the severity of the infection is usually milder than those whom are not infected.

Source: UptoDate, WHO, CDC