Which STDs Is the Tzanck Test Used For?

The Tzanck test (or smear) is a test that can be used to detect members of the viral family herpesviridae. This means that, in addition to detecting conditions such as chickenpox and shingles, the Tzanck smear can detect infection with herpes simplex viruses, which can cause genital herpes (as well as cold sores).

Uses

• The Tzanck test can only be used to identify viruses related to herpes and can only be used to confirm the presence of a herpetic condition. The Tzanck test cannot be used to diagnose non-herpetic STDs.

Procedure

• A Tzanck smear tests fluid from a blister. A scalpel is used to obtain a sample from the base and sides of a blister, and the sample is then stained to detect multinucleated giant cells, very large cells with multiple nuclei.

Advantages

• The Tzanck test is accurate, although the accuracy of results increases as does the skill level of the person performing the test. It is recommended for doctor's office settings as it does not require special lab equipment.

Disadvantages

• The Tzanck test cannot detect the differences between herpes viral infections, meaning that it cannot differentiate varicella from genital herpes. However, other diagnostic criteria can be used to determine which infection a patient has.

Other Testing

• Although Tzanck testing cannot be used to detect other STDs, there are reliable tests for most STDs. These might include blood tests, physical examinations or samples taken from discharge or manifestations of the infection.