You are here:

Sexually Transmitted Diseases/Black spot on Glans Penis and External Sphincter


Black spot or dead skin on glans penis
Black spot or dead ski  
Dear Dr. Mark,
I have 3 dark spots on my glans penis and 1 spot around my external sphincter. The first spot was started 14 months ago with the one on my external sphincter. Both of the spot are the darkest as you can see in the attach picture. Four weak ago another 2 spots are appeared. They are not too dark as the others yet. But as time goes by the are getting darker and darker. It took almost two months to be come darkest ( i called the highest stage) based on the formers spot. All of the spots have the same procedure. The started with little brown or black spot and getting darker and darker as time goes by.
I noticed the first spot during my shower after i had sex with a girl with no protection. I am 27 years old from Chiang Mai, Thailand. I feel no pain or itches and any other symptoms. I took some common STD test and HIV test but the results show negative. I'm getting paranoid now, should i need to take all kind of STD test or again? it is a pre-skin cancer?
Please, help me to identify what kind of disease it is and the causes. Would it be cured with a proper medication?

With Thanks,

Hello Saranyu,
All four of the areas photographed appear to be thinning areas of skin allowing underlying bloood vessels to become more apparent.  My guess is that you are UNCIRCUMCISED, and the skin on the glans is easy to wear away during friction from sex.  When this protective skin wears away (from having sex), than underlying redness is apparent.  These areas may appear darker, because they pooling blood from dilated capillaries appears that way.  

In any event, this does not reflect a disease or STD.  However it is always good to have routine STD tests, and a blood test (or rapid test) for syphilis is suggested.  You mentioned having had a "common" STD test but such tests may not be the same in every locality.  

Good luck!

Sexually Transmitted Diseases

All Answers

Answers by Expert:

Ask Experts


Mark P. Behar


Almost any question or concern about gay men's health issues, sexually transmitted infections, abnormal Pap smears, anal cytology (anal "Pap smears"), etc. There is no such thing as “d/d free” or “clean” (free of infection), so why do so many of us deceive ourselves into thinking that some people are indeed totally free from a potentially infectious disease, like HIV, herpes, hepatitis, syphilis, chlamydia, warts, gonorrhea, etc., just because they say so? Clinical laboratory tests are not perfect, and having a “negative” or “nonreactive” test does not mean that a person is free from infection. Perhaps at the moment the test was taken, the person was uninfected; or, perhaps, the test wasn’t sensitive enough to detect presence of the infection. There is really no way that anyone can determine that they are truly “disease free,” and there are over a hundred of infectious conditions that can be spread without your knowing anything. Rather than trying to “pre-screen” or “serosort” a potential sex-mate with deceptive questions that are impossible to know by today’s technologies, a wiser option may be to consider everyone infected with something, and either use appropriate protective measures (“safer sex”), or accept the responsibility and consequences of possibly “catching” something from someone who’s hotter than expected (pun intended!). There is much research that supports the contention that an HIV positive person reliably taking HIV medications, and having an undetectable viral load, presents a lower risk for transmission of HIV than people who may think or say they are HIV negative, but are not. Food for thought!


Family Practice PA since 1981; Volunteer Clinician for Brady East STD (BESTD) Clinic, Milwaukee, since 1977; answered STD questions submitted to their web site. Professionally lectured at national and regional Physician Assistant and Nurse Practitioner conferences, and at national gay & lesbian health conferences on topics including HIV/AIDS, herpes, hepatitis, STDs, human papilloma virus (the cause of venereal warts), abnormal Pap smears, gay and lesbian health issues, among others.

Co-Founder, Lesbian, Bisexual, & Gay Physician Assistant Caucus of the American Academy of Physician Assistants, Inc.; American Academy of Physician Assistants; Wisconsin Academy of Physician Assistants; National Co-Chair (2012-16), National Association of Black and White Men Together: A Gay, Multiracial Organization for All People (NABWMT)

Journal of the American Academy of Physician Assistants (JAPA) Q Visions, Quarterly Newsletter of the NABWMT

Bachelor's of Arts, 1972 (University of Wisconsin, Milwaukee, WI) Graduate Credits Experimental Psychology, 1972-75 (Tulane University, New Orleans, LA) Physician Assistant, Bachelor's of Science, 1981 (George Washington University, Washington, DC); Masters in Physician Assistant Studies, 2000 (University of Nebraska Medical Center, Omaha, NE)

Awards and Honors
Colposcopy Recognition Award (CRA), the American Association of Colposcopy and Cervical Pathology; Distinguished Fellow, Clinical Preceptor, American Academy of Physician Assistants; Fellow, Wisconsin Academy of Physician Assistants

Past/Present Clients
Brady East STD Clinic, Milwaukee, WI Milwaukee Health Services, Inc. (Martin Luther King Heritage Health Center), Dept. of Family Medicine and Early Intervention Program for HIV Infected Persons

©2017 All rights reserved.