QUESTION
I've been having recurring sores on my penis since August. I have been tested for hsv-1 and it came back negative. I was tested with a swab for hsv-2 and a blood test twice and they all came back negative. Is it possible I have genital herpes because sores on my penis have recurred once again?

ANSWER
Doctors cannot make a diagnosis over the Internet. San Francisco City Clinic offers expert clinical evaluation in all areas of sexual and reproductive health, www.sfcityclinic.org. Herpes tests can be confusing and different tests tell the doctor and patient different things. There are blood tests and swab tests for herpes. If blood tests are negative (normal) for both types of herpes that means that the patient has not been infected with the herpes virus. The blood tests, however, can be negative (normal) if the tests are done too soon (within one month) after initial infection. It takes time for the blood tests to turn positive after infection. Whereas swab tests can be negative if the tests are done too late in the course of an outbreak.

There are a variety of diseases, skin and dermatological, conditions that can cause recurrent penile sores. Herpes is certainly a common cause of genital sores but allergic reactions to medications, auto-immune conditions and trauma during sex without adequate lubrication can also cause recurrent sores.

For more information on STD testing, visit http://SFCityClinic.org [SFCityClinic.org] for places in San Francisco, try http://STDTest.org or call the CDC National Hotline for services near you: 1-800-CDC-INFO.

To your health,
Dr. K