The Brain and Spine Institute is made up of experts in the field of neuroscience in order to bring patients the best healthcare in East Tennessee for a full range of neurological diseases and disorders.
myClipboard
myClipboard
Save news, events, articles and doctor's information to your personal clipboard for later reference.
Add items by clicking the 
button.
Create an account
Centers of Excellence
-
-
We provide a comprehensive continuum of cancer services, including prevention, outreach, diagnostic, treatment and support services delivered by our highly skilled staff with compassion and care.
-
The Center for Women & Children's Health is a hub for supporting women's and children's individual healthcare needs. The center provides support, research and unmatched patient-centered care.
-
Emergency and Trauma Services is the only Level I Trauma Center in the area and serves as the tertiary referral center for medical care in East Tennessee, serving Knox County and 21 surrounding counties.
-
The Heart Lung Vascular Institute brings together expertise in clinical care, teaching and research. Patients receive exceptional healthcare combined with patient-centered care.
Share
Print
Related Media
Wood's lamp examination
Definition
A Wood's lamp examination is a test that uses ultraviolet light to closely look at the skin.
Alternative Names
Black light test; Ultraviolet light test
How the test is performed
The test is done while you are seated in a dark room, usually in a dermatologist's office. The health care provider turns on the Wood's lamp, holds it 4 to 5 inches from the area of skin being studied, and looks for any skin color changes.
You should not look directly into the light.
How to prepare for the test
No special preparation is needed. If you are treating the area in question with any topical medications, you may wish to skip an application before visiting the doctor.
How the test will feel
You will feel nothing during this test.
Why the test is performed
Your health care provider may perform this test to detect several conditions affecting the skin, including
- Bacterial infections
- Fungal infections
- Porphyria
- Skin coloring changes
Normal Values
Normally your skin will not shine, or fluoresce, under the ultraviolet light.
What abnormal results mean
A Wood's lamp exam may help your doctor confirm a fungal infection or bacterial infection. Your doctor may also be able to learn what is causing any light- or dark-colored spots on your skin.
What the risks are
There are no risks. Avoid looking directly into the ultraviolet light.
Special considerations
Do not wash before the test, because that may cause a false-negative result. A room that is not dark enough may also alter results. Other materials may also glow. For example, some deodorants, make-ups, soaps, and even lint may be visible with the Wood's lamp.
Not all types of bacteria and fungi can be detected with the light.
References
Morelli JG. Evaluation of the patient. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 644.
Harrison S, Piliang M, Bergfeld W. Hair disorders. In: Carey WD, ed. Cleveland Clinic: Current Clinical Medicine 2010. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2010.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).