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Skin lesion aspiration

Skin lesion aspiration is the withdrawal of fluid from a skin lesion (sore).

How the Test is Performed

A needle is put into skin sore or skin abscess, which may contain fluid or pus. The fluid may be examined under a microscope. A sample of the fluid may also be sent to a lab. There, it is put in a lab dish (called a culture medium) and watched for growth of bacteria or fungi.

How to Prepare for the Test

You do not need to prepare for this test.

How the Test Will Feel

The health care provider may inject a numbing medicine (anesthetic) into the skin before inserting the needle if the sore is deep.

You may feel a pricking sensation as the needle enters the skin.

In many cases, removing the fluid will lessen pressure within the skin sore and ease pain.

Why the Test is Performed

This test is used find the cause of a fluid-filled skin lesion. It can be used to diagnose skin infections.

What Abnormal Results Mean

Abnormal results may be a sign of a infection caused by bacteria, fungi, or viruses.


There is a small risk of bleeding, mild pain, or infection.


Ruocco E, Baroni A, Donnarumma G, Ruocco V. Diagnostic procedures in dermatology. Clin Dermatol. 2011;29:548-556. PMID 21855731 www.ncbi.nlm.nih.gov/pubmed/21855731.

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Update Date 12/2/2014

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