Some research suggests that people with multiple sclerosis (MS) may have a higher prevalence of fungal infections, such as yeast infections, compared with the general population. Many MyMSTeam members report dealing with yeast infections frequently. “Is anyone else dealing with chronic yeast infections?” one member asked.

Fungi and fungal spores are microorganisms commonly found in the environment and typically don’t cause illness or infection in most people. However, for those with MS, several factors may contribute to a greater risk of fungal infection. These include immune system dysfunction, a possible link between MS and fungal infections, and the use of disease-modifying therapies (DMTs) to treat MS.

One MyMSTeam member wrote, “I have another yeast infection — probably my second this year — and I used to never have problems with yeast infections. Has anyone else had this issue?” Another member asked, “Wondering if anyone knows if there’s a correlation between MS and having recurrent yeast infections and jock itch-type symptoms?”

Another team member said, “I had my first yeast infection at 4 months old. The pediatrician wasn’t sure what it was, but his nurse did. I was his first patient with a yeast infection. I saw him a lot in my youth, and always with weird problems that normal kids did not experience.”

If you think you might have a fungal infection, it’s important to talk to your doctor. They can help find the cause and recommend the most effective treatment.

Common Types of Fungal Infections

Two of the most common types of fungal infections — or mycoses — seen in people with MS are caused by fungal species in the genuses Candida and Tinea. Candida albicans (C. albicans) is a common Candida species that causes vaginal candidiasis and thrush. Tinea infections include ringworm, athlete’s foot, and jock itch. Fungal infections usually develop either through contact with fungi in the environment or from an overgrowth of fungi that naturally live on the body. Sometimes fungal infections can be contagious and spread from person to person.

Are Yeast Infections Common With MS?

Research published in the journal Neurobiology of Disease has found that people with MS tend to have higher levels of fungal antibodies in their bloodstream and in cerebrospinal fluid, which is part of the central nervous system. However, specific research on yeast infection rates in people living with MS is still limited.

So far, the only autoimmune disease known to directly cause yeast infections is autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).

Vaginal Candidiasis

Vaginal candidiasis, also known as candidal vulvovaginitis, is a Candida infection more commonly known as a vaginal yeast infection. It’s caused by the overgrowth of Candida fungus. Vaginal yeast infection symptoms can include swelling, pain, small cuts in the vagina and vulva, thick white discharge, itching, and a burning sensation when urinating. Though less common, candidiasis can also occur in the penis, usually causing an itchy rash.

Risk factors for vaginal yeast infections include diabetes, pregnancy, hormonal contraceptive use, and a weakened immune response, which can happen in people who are immunosuppressed.

Some people may wonder: Does stress cause yeast infections in the vagina? In fact, stress related to trouble sleeping, illness, or poor diet may increase the risk of yeast infections.

Mild vaginal yeast infections are usually treated over the course of several days with oral or topical antifungal medications. Common short-term treatments include miconazole, an over-the-counter cream that is inserted into the vagina, and terconazole, a prescription cream.

The drug fluconazole is an oral antifungal medication for vaginal yeast infections that is taken as a single dose.

Thrush

Thrush is another form of yeast infection caused by the Candida fungus. Unlike vaginal candidiasis, thrush usually affects the mouth, throat, or esophagus rather than the vagina. Symptoms include thick, white lesions in the mouth resembling cottage cheese, soreness, redness, cracked skin at the corners of the mouth, and loss of taste. In more severe cases, thrush can cause fever and may spread to the skin, liver, or lungs. Risk factors for thrush include diabetes, dry mouth, smoking, and the use of certain medications such as corticosteroids, antibiotics, and oral contraceptives.

People with weakened immune systems are at a higher risk for thrush, a contagious fungal infection. Thrush is usually treated with antifungal medications applied to the inside of the mouth. In more severe cases, antifungal drugs may be given intravenously.

One MyMSTeam member shared, “My throat is feeling a bit better. It’s been bad for a month. I’m taking antifungal medication.”

Tinea Infections

Tinea refers to a group of closely related fungal infections caused by dermatophytes — fungi that thrive in warm, moist areas and can live on the skin, hair, and nails. Tinea infections include:

• Ringworm
• Nail fungus
• Athlete’s foot
• Jock itch

One type of tinea infection, ringworm, can happen on the scalp and may start as small sores that become flaky and scaly lesions. The scalp may ooze, swell, or become discolored and tender.

On the skin, ringworm often appears as a discolored round patch. When it affects the nails, ringworm can cause thickening, discoloring, or crumbling.

Ringworm can be stubborn to treat. Treatment options include oral or topical antifungal cream or shampoo, depending on the area affected.

“I have a ringworm infection,” shared one MyMSTeam member. “My general practitioner says it’s nothing major, but it is one of the skin infections I am now prone to.”

Athlete’s foot is a tinea infection that typically starts as an itchy, scaly rash between the toes and can spread to other parts of the foot. It can also cause symptoms such as a burning sensation or blisters. Over-the-counter antifungal treatments are often effective, but if symptoms persist or if you have diabetes, you should see a doctor.

Jock itch is a scaly, itchy rash that appears in the genitals, buttocks, or inner thighs. Keeping affected areas dry and using over-the-counter antifungal treatments can help relieve symptoms.

Fungal Infections and Disease-Modifying Therapies for MS

Disease-modifying therapies (DMTs) are a common treatment for MS. These therapies work by modifying and sometimes suppressing the immune system, particularly in people with autoimmune diseases such as MS. However, when the immune system is suppressed, the risk of infections increases, including fungal infections.

One research review found an association between certain DMTs commonly used to manage MS and an increased risk of invasive fungal infections. Invasive fungal infections are those that are severe, systemic, and potentially life-threatening. However, the risk of fungal infection while taking DMTs is considered low.

The research study found that some DMTs used to treat MS — particularly monoclonal antibody treatments — were more commonly associated with invasive fungal infections compared to other DMTs. Two of the most frequently observed fungal infections were:

• Aspergillosis, a rare respiratory illness caused by the Aspergillus fungus
• Cryptococcal meningitis, a serious brain infection caused by the Cryptococcus fungus

If you’re concerned that your DMT could increase your risk of yeast infections or other fungal infections, talk to your healthcare team.

Although DMTs suppress the immune system and raise the risk of infection, they are still highly effective treatment options for many people with MS. Your doctor will weigh the pros and cons of DMTs when recommending a treatment plan for your MS, and if you start a DMT, your care team will monitor you closely for signs of infectious diseases.

Theory: Could a Fungal Infection Trigger MS to Develop?

Neurology researchers have suggested that some type of infectious pathogen — a bacterial, viral, or fungal microorganism — may trigger the pathogenesis (onset) of MS. While the root cause of MS is still not fully understood, a study from 2018 found evidence of fungal infections in central nervous system (CNS) tissue from people with MS. However, this finding doesn’t prove that the fungal infections caused MS in study participants. It simply shows a potential association.

Another recent study looked at the gut microbiome of people with MS. It found that people with MS have an abnormal balance of gut microbiome (dysbiosis) — the naturally occurring bacteria and fungi found in the gastrointestinal tract. The study showed that people with MS have more types of fungi, particularly Candida albicans, compared to people without MS. In MS, an abnormal immune response targets the protective covering of nerve fibers (demyelination). Researchers are investigating whether this fungal imbalance might contribute to this inflammation.

Understanding what causes MS could lead to better and more targeted treatments in future. For now, however, the theory that fungal infections could trigger or worsen MS is still preliminary, and more research is needed.

Talk With Others Who Understand

MyMSTeam is the social network for people with multiple sclerosis and their loved ones. Here, members come together to ask questions, give advice, and share their stories with others who understand life with MS.

Do you have questions about yeast infections or other types of fungal infections and MS? Share your experiences or questions in the comments below, or start a conversation by posting on your Activities page.