Expert Answers Factual Answers to Your Sexual Health Questions

anonymous on September 12, 2011

Do STDs ever develop on their own?

If I had sex with my girlfriend, and neither of us has a sexually transmitted disease (STD), can an STD form on its own? Also, I’ve had unprotected sex with my girlfriend using baby oil, and now I have little pimples or blisters on the bottom of my head of my penis. Could that be from the baby oil? Or could it be something else?

answered by Linda Lesondak, PhD on September 12, 2011

Thank you for writing. There’s a lot of misinformation out there about what STDs are and how they spread. I’ll do my best to clear up your questions.

First, the short answer is no: if you’re in a mutually monogamous relationship (meaning you only have sex with each other) and both of you are STD-free, an STD cannot form on its own. That said, are you sure that you’re both STD-free?

The reason I ask is that many STDs don’t show any symptoms...at least not at first. You can’t tell if someone has an STD just by looking. And if someone is infected with an STD, they can pass the infection to a sexual partner...even if there are no visible symptoms or signs of an STD.

Also, keep in mind that doctors often don’t automatically screen for STDs. For example, if your girlfriend’s gynecologist gave her a Pap test, she would have only been screened for certain types of human papillomavirus (HPV). She would still need to be tested for other common STDs including herpes 1 & 2, hepatitis B and C, HIV, syphilis, gonorrhea and chlamydia.

To know for sure if either of you has an STD, make an appointment for STD testing with your doctor or look into reputable online testing services. In the meantime, using barrier protection like condoms and dental dams is a good way to reduce the risk of catching STDs...and reducing the risk of unintended pregnancy.

About the pimples or blisters on your penis...yes, the baby oil you used could be the cause.

Or, your symptoms might indicate a sexually transmitted infection like genital herpes or genital warts. But, again, the only way to know the cause of your symptoms for sure is to see your regular doctor, and get tested for STDs. If you’d like more information about STD risks, symptoms, prevention and testing, see our Expert Guide to STD Basics.

One more item for your consideration and safety...

In future, I encourage you to use water-based lubricants instead of oil-based lubricants (like baby oil). Why? Because using oil-based lubricants with latex condoms ⎼ for as little as 60 seconds ⎼  has been shown to decrease the strength of latex condoms by 90%, as documented in a study by the Mariposa Foundation, and published in the journal Contraception. Using baby oil with latex condoms reduces the ability for condoms to protect against STDs or unintended pregnancy.

Thanks again for your questions, and I wish you and your girlfriend good health and sexuaI well-being.

Related Info:

Linda Lesondak, PhD

Dr. Lesondak is a Community Psychologist with the Chicago Department of Public Health. Her areas of expertise include STDs, HIV, preventive care, public health and community planning, as well as human sexuality and women’s health. Dr. Lesondak was educated at Georgia University in Atlanta.

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