Candidiasis, commonly known as a yeast infection, is caused by an overgrowth of the fungus Candida, most often Candida albicans. This organism is a natural part of the human microbiome, existing harmlessly in small amounts on the skin, mouth, and genital tract. A yeast infection occurs when this fungus multiplies rapidly, overwhelming the body’s natural balance of microorganisms. While candidiasis is not typically classified as a sexually transmitted infection, the transfer of the fungus through oral sex is possible and can trigger an infection in either partner.
The Biological Mechanism of Transmission
The transfer of Candida during oral sex occurs primarily through direct contact between a site with a fungal overgrowth and a healthy mucosal surface. Candida thrives in warm, moist environments, making both the mouth and genital area ideal habitats. If one partner has an active infection, a high concentration of the fungus is present at that site.
If the genital area has an active infection, a large volume of Candida can be transferred to the mouth, overwhelming the existing microbial balance and leading to oral thrush. Conversely, if the person performing oral sex has oral thrush, the fungus can be transferred to the genital area.
More complexly, the very act of oral-genital contact can trigger an infection, even without an active fungal overgrowth in the mouth. Human saliva has a different pH level compared to the naturally acidic environment of the vagina. Introducing saliva can temporarily disrupt the delicate balance of the vaginal microbiome, which is usually maintained by beneficial bacteria like Lactobacillus. This pH change inhibits the growth of these protective bacteria, allowing the naturally present Candida to multiply rapidly and cause an infection.
Recognizing Oral Thrush
A yeast infection in the mouth is medically termed oral candidiasis or oral thrush. This condition results from fungal overgrowth on the mucous membranes of the mouth and throat. The most noticeable symptom is the appearance of creamy white, slightly raised lesions or patches inside the mouth.
These lesions often resemble cottage cheese and are typically found on the tongue, inner cheeks, roof of the mouth, or tonsils. Attempting to scrape these patches away may cause slight bleeding or reveal an underlying red, raw surface.
Other symptoms include redness, soreness, a burning sensation, or a cottony feeling inside the mouth. Severe cases can make eating or swallowing difficult and painful. These oral signs are distinct from a genital yeast infection, which typically involves itching, burning, and a thick, white discharge.
Preventing Transmission and Reducing Risk
Proactive measures can significantly lower the risk of transmitting or acquiring a yeast infection during oral sex. The most direct method is using barrier protection to prevent the exchange of fluids and microorganisms. Dental dams or a cut-open non-lubricated condom can be placed over the genital area to create a physical barrier between the mouth and the skin.
If an active infection is known, whether oral or genital, avoid oral sex until treatment is complete and symptoms have resolved. Engaging in sexual activity during an active infection increases the concentration of Candida available for transfer. Open communication with a partner about current symptoms can guide safer practices.
Maintaining good overall hygiene, particularly around the genital area, helps keep Candida populations balanced. Avoiding irritating products like perfumed soaps or douches on the vulva is advisable, as these disrupt the natural vaginal pH and increase vulnerability to overgrowth. Consistent use of a barrier method offers the best protection against microbial transfer and pH disruption, especially for partners with recurring infections.
When to Seek Professional Help and Treatment
Consulting a healthcare provider is necessary for accurate diagnosis and proper treatment when yeast infection symptoms are present. While over-the-counter treatments exist, a professional can confirm the symptoms are caused by Candida and not another condition. This is important if the infection is persistent, severe, or recurrent.
Treatment for oral thrush often involves topical antifungal medications, such as lozenges that dissolve in the mouth or an antifungal mouthwash. These treatments work directly on the mouth’s surface to reduce the fungal population.
For genital infections, treatment typically includes antifungal creams, ointments, or suppositories applied locally. Sometimes a single dose of an oral antifungal medication, such as fluconazole, is prescribed.
Treatment duration usually ranges from seven to fourteen days, depending on severity. It is important to complete the entire course of medication as prescribed, even if symptoms clear up sooner, to ensure the fungal overgrowth is fully eradicated. Stronger or systemic oral antifungal drugs may be prescribed for individuals with compromised immune systems or those whose infections do not respond to standard treatment.