What is a yeast infection?

A yeast infection is a fungal infection caused by an overgrowth of certain fungal species (most commonly from the Candida family). For yeasts to cause infection, there must be a change in the balance of the normal microbiota (environment of microorganisms). This shift in balance causes an overgrowth of Candida species. The immune system then responds to this overgrowth by inducing a range of symptoms, such as:

• Inflammation
• Itching
• Small bumps and blisters
• Burning sensation on the head of the penis and under the foreskin
• Pain during sex and urination
• White, lumpy and foul smelling discharge

Yeast infections can occur in various parts of the body, including the mouth, skin, vagina and penis.

What is candida?

Candida is a type of fungus that naturally lives in the human body. In 50% of the human population, Candida albicans is a part of the normal microbiota, and so it normally causes no concern for our health.¹ 

Common misconceptions about yeast infections

A common misconception is that yeast infections are only vaginal and therefore a problem for females only. Although yeast infections are more common in the vagina, there is growing concern for penile yeast infections as studies show that approximately 16-26% of men do carry Candida on their genitalia.² Approximately 37% of people with penises who carry Candida express no symptoms; however, 27% have developed balanitis, an inflammatory condition of the penis and foreskin that can be caused by Candida species (candidal balanoposthitis).³

Other misconceptions and stigmas are that those with urogenital yeast infections are dirty and unhygienic. This is not the case at all. Yeast infections often occur due to overgrowth of Candida and fungal species which can be triggered by many external factors such as lifestyle.¹ Hygiene does have an impact on yeast infections; however, it is not always the sole cause.

Why study male yeast infections?

Many males with yeast infections are asymptomatic.⁴ This can be dangerous as it can lead to no diagnosis at all. Further complications can arise when asymptomatic male carriers of Candida engage in sexual activities or unprotected sex.⁵ If this involves females, the undiagnosed and asymptomatic male can infect their female partner with Candida, potentially causing a more persistent yeast infection in the female partner.⁵ This can also contribute to recurrent infections in females. Therefore, studying male yeast infections can help reduce transmission between partners, encouraging communication and safer sexual practices.

Additionally, male yeast infections can be more severe, harder to treat and even spread to other organs if the male is immunocompromised with other diseases such as HIV/AIDS and diabetes.⁶ Therefore, it is essential to study male yeast infections to improve patient outcomes and quality of life.

Pathogenicity of candida albicans

Although Candida is usually harmless, it can become opportunistic and initiate infection (candidiasis) in its host. C. albicans has many factors which aid its ability to cause an infection. For example, C. albicans can switch between different structures based on environmental conditions such as temperature (this is known as thermal dimorphism).⁷

In thermal dimorphism, Candida enters the body in a round and single celled yeast form that is typically harmless. It can colonise a small area and grow harmlessly. The Hyphal form is filamentous form consisting of multiple long cells rather than single cell yeasts. This allows C. albicans to spread to other tissues and infect them via invasion and damage. These forms can attach to the endothelial cells of different organs and penetrate blood vessels.⁷ Adhesion can also occur on invasive hospital equipment, such as catheters, initiating urogenital yeast infections. Created in https://BioRender.com 

In the case of male yeast infections, C. albicans will reside on the surface of the penis as a yeast, this is usually in moist conditions and under the foreskin but is usually non-infectious (26% of healthy men carry Candida on their genitals).² If environmental changes occur this can trigger a switch to hyphal growth. Hyphal growth invades the tissue of the penis often causing symptoms such as itching or burning, thick white discharge and painful urination. 

Other candida species in male yeast infections

Although Candida albicans is the main fungal species involved in yeast infections, other Candida species have also been shown to also cause infections in males. These include Candida glabrata and Candida tropicalis. Since these species differ from C. albicans, they often infect hosts in different ways and must be studied to effectively treat male yeast infections.

Candida glabrata

Candida glabrata is less infectious compared to C. albicans. Like C. albicans, C. glabrata is a known coloniser of many surfaces in the human body, including the oral cavity and even urogenital sites such as the glans penis in males. It is not limited to life inside the human body, it can also grow on surfaces such as mobile phones and be found in nature, such as in coffee beans and bird droppings.

C. glabrata is different from C. albicans as it is unable to form hyphal structures (as shown in Figure 1). Instead, C. glabrata spreads by forming biofilm (an infectious film containing a community of microorganisms). This biofilm can grow on any surface and often occurs in hospital equipment such as catheters and cannulas. C. glabrata is also more resistant to antifungal drugs (azoles) and so it is much harder to treat than C. albicans infections.⁸

Symptoms of yeast infection and balanitis by C. glabrata include:

• Less inflammation compared to C. albicans
• Minimal redness
• Less discharge
• Chronic irritation and itching⁹

Candida tropicalis

Candida tropicalis is genetically similar to C. albicans and accounts for 8% of male yeast infection cases.¹⁰ It is a commensal fungus within the human body, often colonising the gastrointestinal tract, skin and genitals of both men and women. It is also found in nature, including in soil, animals and decaying organic matter.¹⁰

Like C. albicans, C. tropicalis can switch from yeast to hyphal form within the body in favourable conditions. Additionally, C. tropicalis also has the ability to produce biofilm, like C. glabrata.C. tropicalis also shows tight adhesion to surfaces in the body such as the skin, with environmental conditions such as moisture and sweat aiding this activity.¹⁰ These factors increase the pathogenicity of C. tropicalis, making it more infectious and harder to treat. 

Risk factors for male yeast infections 

Candida yeast infections in males are induced by a range of factors related to health and lifestyle. A key reason why men suffer from yeast infections is antibiotic use. Whether this is for a bacterial infection or overuse, using antibiotics kills bacteria in the body, even healthy bacteria. This disrupts the balance in the microorganisms, and fewer bacteria, there are more nutrients and space available for fungi such as Candida.¹¹ This allows Candida to overgrow, increasing its chances of survival and movement to other areas of the body, initiating infection. 

Diagnosis of candida yeast infections

The first step in diagnosing male yeast infections involves check-ups and physical examinations for symptoms.¹³ If symptoms are present, the second step is to confirm whether it is actually a yeast infection.

As the symptoms of a yeast infection are non-specific, they could occur due to bacterial and sexually transmitted infections.⁴ Lab diagnosis helps to confirm whether Candida is the cause of the symptoms. A sample of smegma or discharge from the penis is usually taken and observed under a microscope.¹³

Under the microscope, C. albicans would show budding yeast cells and hyphae (see Figure 1). C. glabrata would present just budding yeast cells and C. tropicalis would show both. This is a cheap and easy method of testing for yeast infections with results being quick; however, it is not sensitive enough to detect low levels or early infection.¹³

Treatments options

Male yeast infections are often treated with antifungal creams such as nystatin and clotrimazole creams. These are applied directly on the affected areas of penis for approximately 1-2 weeks. Oral antifungals are used when topical antifungals fail to clear the infections, these include fluconazole and itraconazole.¹⁴

Prevention strategies

Lifestyle changes such as maintaining good genital hygiene (whether circumcised or uncircumcised), regular changing of clothes and avoiding irritants in soap and cream products helps to prevent yeast infections and aids treatment. Additionally, addressing underlying health issues such as high blood sugar and controlling diabetes can reduce the risk of contracting yeast infections as well as maintaining a routine healthy diet. 

Summary

Candida is a family of fungi that is a part of the normal microbiota on the skin, mouth, gastrointestinal tract and genitals.

In males, overgrowth of the Candida species, specifically Candida albicans, Candida glabrata and Candida tropicalis, can cause yeast infection, typically affecting the head of the penis and foreskin, causing an inflammatory condition known as balanitis.

Overgrowth of Candida is triggered by warm, moist environments often due to poor hygiene or tight clothing. Other risk factors include antibiotic usage, weakened immunity and regular use of fragrant hygiene products.

Candida can switch from yeast form (safe) to hyphal form (invasive) depending on temperature conditions - thermal dimorphism. This hyphal form allows Candida to penetrate tissues and helps Candida to avoid immune clearance.

Yeast infections are diagnosed by check ups and lab testing of smegma/discharge samples from the penis. For more accurate results, molecular testing can be carried out which would detect lower levels of infection. Proper and regular hygiene helps to prevent male yeast infections, as well as drying the genital area thoroughly after washing and wearing loose, breathable underwear and clothing. Open communication with partners helps to prevent sexual transmission of yeast infections. Keeping a healthy diet and controlling underlying health conditions also helps to prevent infection.