It is important for people with diabetes to recognize symptoms of a fungal infection and to receive prompt treatment to avoid potentially serious complications.
Yeast is present in the skin and near mucous membranes. It helps keep neighboring bacteria in check. However, if too much yeast collects, candidiasis — more commonly known as a yeast infection — can develop. It can cause discomfort, including pain and itchiness.
Yeast is most likely to grow excessively in areas that are warm and moist, including the mouth, the genital area, the feet, and in skin folds.
Bacteria, viruses, and fungi, including yeast, can cause infections if a person’s immune system cannot control the levels in the body.
As a 2018 study — which included data from over 300,000 people — showed, a person with type 1 or type 2 diabetes has a higher risk of infection, including yeast infection, than a person without the condition.
In people with diabetes, symptoms can grow worse more quickly than in other people. Also, infections can be harder to treat. If an infection does not heal, it can lead to complications.
A person with poorly controlled diabetes has an increased risk of more severe and frequent yeast infections.
Researchers are still trying to pinpoint the link between yeast overgrowth and diabetes. It could involve the following factors.
Compromised immune system
Scientists have found associations between diabetes and immune dysfunction.
Type 1 diabetes happens when a problem with the immune system results in damage to cells in the pancreas. Immunological changes and increases in inflammation also appear to play a role in developing type 2 diabetes.
Poorly controlled diabetes may hinder the immune response. This could be part of the reason why having diabetes makes a person more prone to yeast infections.
Research into the exact relationship between diabetes and the immune system is ongoing. One theory is that high blood sugar leads to the suppression of certain immune proteins.
These proteins — called beta-defensins — help immune cells move toward infections and kill the microbes. If a condition, such as diabetes, inhibits these functions, a yeast infection could thrive unchecked.
Extra sugars in yeast-friendly areas
Diabetes can also make it easier for yeast and other pathogens to cling to skin cells and mucus glands. This may be because of the presence of extra sugars, which allow yeast to colonize at unhealthy levels.
When blood glucose levels are high, the body may excrete extra sugar in the:
Yeast feeds on sugar, making these secretions the most likely factor in overgrowth.
People with diabetes also have increased levels of glycogen, a polysaccharide that the body uses to store glucose. Extra glycogen in the vaginal area can lead to an increase in acidity. This can contribute to yeast growth, according to a study published in 2009 in the American Journal of Obstetrics and Gynecology.
Once yeast has colonized in an area, it becomes easier for an infection to return. A person who is susceptible to yeast infections, due to difficulty managings diabetes, will also have a higher risk of recurring problems.
Yeast infections can manifest differently in different parts of the body.
Skin infection: The skin may change color, or there may be itchy patches of varying shapes and sizes.
These symptoms usually develop in skin folds, but they can spread to other parts of the body, including the face or trunk. A yeast infection can also affect the scalp.
The name for a yeast infection in the skin is cutaneous candidiasis.
Genital infection: These are more common in females than in males, but a male who has difficulty managing their diabetes may have a higher risk.
A female may notice:
- vaginal itching or pain, including a burning sensation
- a white, cottage cheese-like discharge
- a burning sensation or another type of pain while urinating
- an unpleasant odor
A male may have an itchy, scaly rash on the penis.
Anyone with diabetes who notices these symptoms should see a doctor because they are likely to need treatment. Without treatment, complications can occur.
Eye infection: Symptoms include pain, redness, blurred vision, discharge, sensitivity to light, and watery eyes. Without treatment, it can lead to vision loss.
Foot infection: Athlete’s foot is a common fungal infection.
For a person with diabetes, damage to the skin on the feet can lead to ulceration and, in some cases, the need for amputation. Nerve damage and circulatory problems that occur with diabetes can make this more likely to happen.
It is important to take measures to prevent fungal infections on the feet. Inspect the feet regularly and receive prompt treatment for any indications of an infection.
Oral thrush: According to the Centers for Disease Control and Prevention (CDC), symptoms of oral thrush include:
- white patches on the inside of the cheeks
- redness or pain in the mouth
- cracking and redness in the corners of the mouth
- loss of taste
- a “cottony” sensation in the mouth
A person with diabetes has a higher chance of developing a fungal infection in the mouth for various reasons. Diabetes can cause dryness in the mouth, increased acidity, and high levels of glucose in the saliva.
Without treatment, a yeast infection can become invasive in a person whose immune system is not working properly. It can spread to the bloodstream and from there to other parts of the body. If this happens, the infection can quickly become life-threatening.
A doctor will examine the affected area, and they may take a sample of skin or urine for laboratory testing. They will also ask about symptoms.
If a person who does not have diagnosed diabetes experiences unusually frequent infections, they should speak to a doctor, who may test for diabetes.
Once a doctor identifies a yeast infection, there are several treatment methods to try, depending on the type of infection.
Topical creams or suppositories
A doctor will usually recommend these first, as they work well during the early stages of an infection.
The doctor may prescribe an antifungal cream to apply directly to the affected area for up to 7 days.
Antifungal creams and suppositories are available over the counter, but a person should speak to a doctor before using them.
This is because:
- The problem may not be a yeast infection.
- Using these medications too frequently can cause yeast to become resistant to them.
Oral antifungal medication
If cream or suppository does not work, or if the person has had several yeast infections in a short time, a doctor might prescribe an oral antifungal medication, such as fluconazole (Diflucan).
One dose may be enough to resolve the infection.