From the Guidelines
Chickenpox is highly contagious from 1-2 days before the rash appears until all blisters have crusted over, typically 4-7 days after rash onset. The virus spreads through direct contact with fluid from blisters, through respiratory droplets when an infected person coughs or sneezes, or by touching contaminated surfaces 1. People with chickenpox should stay home from school, work, or public places until all blisters have crusted over to prevent spreading the infection.
Key Points to Consider
- If you've been exposed to chickenpox and haven't had it before or been vaccinated, you may develop symptoms within 10-21 days 2.
- The varicella-zoster virus that causes chickenpox can remain dormant in nerve tissue after recovery and may reactivate years later as shingles.
- Vaccination with the varicella vaccine is the best prevention method, typically given to children in two doses at 12-15 months and 4-6 years of age.
- Antiviral medications like acyclovir may be prescribed for high-risk individuals if started within 24 hours of rash appearance.
Prevention and Treatment
- The average incubation period for varicella is 14--16 days after exposure to rash; however, this period can vary (range: 10--21 days) 2.
- Persons who have progressive varicella (i.e., development of new lesions for >7 days) might be contagious longer, presumably because their immune response is depressed, which allows viral replication to persist 2.
From the Research
Chickenpox Contagiousness
- Chickenpox, caused by the varicella-zoster virus (VZV), is a highly contagious illness that can spread from person to person through direct contact or airborne transmission 3.
- The virus can be spread through respiratory droplets, such as those produced by coughing or sneezing, or by coming into contact with the rash or blisters of an infected person 3.
- People with weakened immune systems, such as those with immunocompromised conditions, are at higher risk of contracting chickenpox and experiencing more severe symptoms 4, 5.
- The use of varicella-zoster immune globulin (VZIG) can help prevent chickenpox in high-risk individuals, such as immunocompromised children and certain neonates exposed in utero 4.
- Antiviral therapy, such as acyclovir, can also be effective in treating chickenpox and reducing the risk of complications, especially in high-risk populations 5, 6.
Transmission and Prevention
- Chickenpox can be prevented through vaccination, and a live attenuated varicella vaccine is now recommended for routine childhood immunization 3.
- Patient isolation and passive prophylaxis with VZIG can also help prevent the spread of chickenpox in high-risk individuals 4, 6.
- Early treatment with antiviral therapy can help reduce the severity of symptoms and prevent complications in people with chickenpox 5, 6.