Chickenpox and Shingles Tests
Reviewed
Also called: varicella zoster virus antibody, serum varicella immunoglobulin G antibody level, VZV antibodies IgG and IgM, herpes zoster test
Chickenpox and shingles tests detect the varicella zoster virus (VZV) or antibodies to it. They are used to confirm infection in people with symptoms (especially those at higher risk of complications) or to check immunity. PCR tests on blister fluid are the most accurate for confirming active infection. Antibody blood tests can show if you have a current or past infection.
Specimen: Blood (from a vein) or fluid from a blister (swab)
Urgent safety information
If you have symptoms of chickenpox or shingles, contact your healthcare provider right away, especially if you are in a high-risk group (pregnant, infant, immunocompromised, etc.). Early treatment can reduce complications.
Why this test may be ordered
- To confirm a diagnosis of chickenpox or shingles when symptoms are not clear or the person is at higher risk of complications
- To check immunity to VZV (e.g., before pregnancy, before immunosuppressive therapy, or after exposure)
Preparation and collection
No special preparation needed.
Blood draw from a vein or a swab of fluid from an open blister. Both take less than five minutes.
For a blood test, you may have slight pain or bruising at the needle site, but these usually go away quickly. There is no risk to having a blister test (swab).
Understanding results
PCR tests on blister fluid are the most accurate for confirming a current infection. Antibody blood tests show if you have a current/recent infection (IgM) or past exposure/vaccination (IgG).
- PCR test (swab): Negative: No VZV genetic material detected. Active infection is less likely. Limitation: False negatives possible if sample is not from active blister Next step: If symptoms persist, your provider may repeat testing or diagnose based on appearance.
- PCR test (swab): Positive: VZV genetic material detected. This confirms a current infection with chickenpox or shingles (depending on symptoms and age). Limitation: PCR is the most useful test for confirming VZV infection Next step: Your provider may prescribe antiviral medicines, especially if you are in a high-risk group (pregnant, immunocompromised, etc.).
- Antibody blood test: IgM positive: Current or recent VZV infection. You may have chickenpox or shingles. Limitation: IgM antibodies appear early; IgG antibodies appear later and persist Next step: If you have symptoms, your provider will diagnose based on the rash and other signs.
- Antibody blood test: IgG positive (IgM negative): Past exposure to VZV (chickenpox or vaccine). You are immune to chickenpox but can still get shingles. Limitation: IgG positive does not protect against shingles later in life Next step: No further action needed for immunity. If you are 50 or older or immunocompromised, ask about the shingles vaccine.
- PCR and DFA tests on swab samples are more accurate than viral culture, but false negatives can occur if the sample is not taken from an active blister.
- Antibody tests (IgM, IgG) indicate past or recent infection but cannot distinguish between current chickenpox and shingles; diagnosis depends on symptoms and age.
What to do next
Your healthcare provider will interpret test results along with your symptoms and risk factors to determine if you have chickenpox, shingles, or immunity from past infection or vaccination. For high-risk groups, early antiviral treatment may be recommended.
- Chickenpox and shingles are caused by the same virus (varicella zoster virus).
- You can have shingles more than once, but it is rare.
- The shingles vaccine (Shingrix) is recommended for adults 50 and older, and for adults 19+ with weakened immune systems.
Evidence source
U.S. National Library of Medicine: Chickenpox and Shingles Tests