Anonymous on September 26, 2011

I have a small, hard, white-colored bump on the underside of my penis...what is it?

About a month or so ago, I noticed a small, hard, white-colored bump on the underside of the penis at the base (about where the scrotum and penis meet). I thought it might be an STD, but it didn’t hurt or itch, so I figured I would just "wait and see." I got tested for HIV and syphilis, and am awaiting results. But now the bump is bigger, bullet-shaped, and somewhat painful and itchy. Any idea what it might it be?

answered by Lisa Oldson, MD on September 26, 2011

Good for you, for taking the initiative to get tested for some common STDs. The only way to know the cause of your genital bump for sure is to visit your doctor for a visual exam and possibly additional STD testing. However, here are some additional thoughts for your consideration:

Yes, a single, growing bump on your penis should be addressed. If you think you’ve been exposed to STDs, one potential cause of bumps in the genital area are genital warts caused by some types of the human papillomavirus (HPV). Only a visual exam by your regular doctor will determine whether or not you have genital warts.

You mentioned you were tested for syphilis...indeed, a lesion as you describe is a potential sign of a syphilis infection. Syphilis lesions can be red or reddish-brown and measure .5 to 2 cm, as noted in Signs and Symptoms of Secondary Syphilis, a study published in the journal Sexually Transmitted Diseases.

You also said you were tested for HIV. Again, that’s a smart precaution...especially if you have reason to believe that you were exposed to HIV.

You might also consider getting tested for other common STDs, including chlamydia and gonorrhea, herpes 1 & 2, and hepatitis B and C. Why? Because if there’s a chance you were exposed to HIV, syphilis or HPV, you might have been exposed to other STDs also.

Also, keep in mind that not all genital bumps are STDs. This could be a cyst, an ingrown hair that has become infected or some other benign condition. The only way to know is to be examined.

Bottom line: I suggest you get tested for common STDs, and see your doctor for a visual examination of your might be that your bump is a harmless skin condition. But the sooner you know what it is, the sooner you can get treated, if necessary, to avoid potentially more serious health problems later.

For more information about STD symptoms, testing, treatment and reducing the risk of spreading or contracating sexually transmitted infections in future sexual encounters, I hope you’ll visit our Expert Guide to STD Basics. We also have expert guides on HIV and syphilis for your reference.

Thank you for your question, and I hope you soon have the right diagnosis and treatment for the bump on your penis.

Related info:

Lisa Oldson, MD

Dr. Oldson is Medical Director of the Analyte Physicians Group. She is on staff at Northwestern Memorial Hospital, as well as Clinical Instructor at the Feinberg School of Medicine, Northwestern University. Her areas of expertise include STDs (with a particular clinical emphasis on herpes), women's health, preventive medicine, diabetes, obesity and weight management, and mood and anxiety disorders. Dr. Oldson was educated at Rush Medical College and completed her residency at Rush-Presbyterian-St. Luke's Medical Center in Chicago, IL.

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