Ear drainage culture
Definition
An ear drainage culture is a lab test. This test checks for germs that can cause infection. The sample taken for this test can contain fluid, pus, wax, or blood from the ear.
Alternative Names
Culture - ear drainage
How the Test is Performed
A sample of the ear drainage is needed. Your health care provider will use a cotton swab to collect the sample from inside the outer ear canal. In some cases, a sample is collected from the middle ear during ear surgery.
The sample is sent to a lab and placed on a special dish (culture media).
The lab team checks the dish every day to see if bacteria, fungi, or viruses have grown. More tests may be done to look for specific germs and determine the best treatment.
How to Prepare for the Test
You do not need to prepare for this test.
How the Test will Feel
Using a cotton swab to take a sample of drainage from the outer ear is not painful. However,
Why the Test is Performed
The test may be done if you or your child has:
- An ear infection that is not getting better with treatment
- An infection of the outer ear (
otitis externa ) - An ear infection with a ruptured eardrum and draining fluid
It may also be done as a routine part of
Note: Ear infections are diagnosed based on symptoms rather than using a culture.
Normal Results
The test is normal if there is no growth on the culture.
Normal value ranges may vary slightly among different labs. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results may be a sign of an infection. The infection can be caused by bacteria, viruses, or fungi.
The test results may show which organism is causing the infection. It will help your provider decide on the right treatment.
Risks
There are no risks involved with swabbing the ear canal. Ear surgery may involve some risks.
References
Player B. Otitis media. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 680.
Shin J, Bellmunt AM. Otitis media with effusion. In: Francis HW, Haughey BH, Hillel AT, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 8th ed. Philadelphia, PA: Elsevier; 2026:chap 193.
Tähtinen PA, Pelton SI. Otitis externa, otitis media, and mastoiditis. In: Blaser MJ, Cohen JI, Holland SM, et al, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 10th ed. Philadelphia, PA: Elsevier; 2026:chap 63.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright ©2026 A.D.A.M., Inc., as modified by University of California San Francisco. Any duplication or distribution of the information contained herein is strictly prohibited.
Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Health. Please discuss with your doctor any questions or concerns you may have.