Tzanck test

Alternative names
Herpes skin test; Chicken pox skin test

Definition
The Tzanck test is a method of testing sores for the herpes simplex virus (which causes cold sores, fever blister, or genital sores), or varicella-zoster virus (which causes chickenpox and “shingles”).

How the test is performed
The sore is scraped and the scraping is put on a slide and stained. The health care provider then examines it under a microscope.

How to prepare for the test
Infants and children:
The preparation you can provide for this test depends on your child’s age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

     
  • Infant test or procedure preparation (birth to 1 year)  
  • Toddler test or procedure preparation (1 to 3 years)  
  • Preschooler test or procedure preparation (3 to 6 years)

How the test will feel
When the sore is scraped or rubbed, there may be mild discomfort.

Why the test is performed
The test may help diagnose or confirm an infection with 1 of these 2 viruses. This test can not distinguish between these two viruses.

Normal Values
No presence of herpes-infected cells in the scraping is normal.

What abnormal results mean
The results are immediately available. If herpes-infected cells are detected, the patient has been infected with one or the other of the following:

     
  • Herpes simplex (which causes cold sores, fever blister, or genital sores)  
  • Varicella-zoster virus (which causes chickenpox and “shingles”).

What the risks are
There are no risks with this test.

Special considerations
There is a high rate of false-negative results even when the virus is present.

Johns Hopkins patient information

Last revised: December 4, 2012
by Janet G. Derge, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.