Sexually Transmitted Infections Spread By Skin Contact

Most sexually transmitted infections spread either by exposure to infected fluids or by direct contact with infected skin. A few, such as pubic lice, can be spread by even more casual contact. However, STI transmission via clothing or other objects is relatively rare.

Several Common STDs Can Spread by Rubbing Skin on Skin

Skin to skin contact STD transmission is possible for a number of different conditions.

The STIs where skin to skin contact poses the biggest risk for transmission include:

Genital and oral herpes. Herpes is the STD people are often most concerned about being spread from skin to skin. Contact with these very contagious sores can pass herpes from person to person. In fact, most people with oral herpes are infected during childhood. Casual contact with relatives can lead to herpes transmission. Genital and oral herpes can also be transmitted via mouth to genital contact. Although HSV-2 somewhat prefers genital infection, HSV-1 can infect either location.
HPV, Both cancer-causing HPV varieties and the HPV varieties that cause genital warts are easily spread through skin contact. Fortunately, there are vaccines that help. The most common cancer and wart-causing varieties can be prevented by early vaccination against HPV. However, ideally, vaccination should occur before people become sexually active. That's why initial vaccination is recommended at age 11 or earlier. It's also why vaccination isn't usually recommended for those over 26.

Syphilis. There is a growing concern about this disease spreading through contact with mouth sores during oral sex. Most people think of syphilis as an easily preventable disease. It is and it isn't. When sores are covered by a condom, condoms help. However, sores in the mouth and on other skin locations may go unrecognized and untreated. Those sores can still be contagious. That's why testing is still important for high-risk groups.

Molluscum contagiosum. This skin disease is more often thought of as a disease of childhood than an STD. However, molluscum contagiosum sores can be spread during sex as well. Although generally a painless infection, if the sores break open, they can become infected by other bacteria. Therefore, it's worth talking to a doctor about treatment. You can also cover sores to prevent skin-to-skin contact since treatment can be difficult.

STIs that are transmitted by skin-to-skin contact may be difficult to fully prevent by safer sex. That's because barriers do not necessarily cover all potentially infectious skin. However, practicing safer sex does reduce the risk of skin-to-skin STI transmission from diseases such as herpes and HPV. The more skin that's covered, the less likely sores are to touch uninfected skin.

In contrast, it is easier to effectively prevent transmission of STIs such as HIV and hepatitis that spread through bodily fluids by using condoms and other barriers. These STIs require exposure to infected secretions such as blood, semen, and vaginal fluids for transmission to take place. (Which secretions are infectious varies by disease.) Remember, though, HIV does not spread by casual contact or skin-to-skin contact.

_Sources:

_{Centers for Disease Control and Prevention (CDC). Transmission of primary and secondary syphilis by oral sex--Chicago, Illinois, 1998-2002. MMWR Morb Mortal Wkly Rep. 2004 Oct 22;53(41):966-8.}

_{Fernando I, Pritchard J, Edwards SK, Grover D. UK national guideline for the management of Genital Molluscum in adults, 2014 Clinical Effectiveness Group, British Association for Sexual Health and HIV. Int J STD AIDS. 2015 Sep;26(10):687-95. doi: 10.1177/0956462414554435.}

London S. Consistent use of condoms lowers the risk of infection with type 2 herpes virus. Int Fam Plan Perspect. 2006 Mar;32(1):53-4.

_{Wald A. Genital HSV-1 infections. Sex Transm Infect. 2006 Jun;82(3):189-90.}