Fungal Infections: Information & Specialists in Fungal Infections

Fungal infections, also known as mycoses, are infectious diseases. They are caused by certain disease-causing fungi.

Mycoses can be classified according to various criteria. The most common classification is based on

• location (where they occur),
• the fungal infection and
• the type of pathogen (DHS system according to Rieth).

In terms of location, a basic distinction is made between

• local or superficial fungal infections and
• systemic mycosis.

The classification into superficial and systemic mycoses distinguishes fungal infections based on their location.

Local or superficial fungal infections

Local mycoses are superficial fungal infections. They are generally limited to a specific part of the body or a specific tissue (topical mycosis). This means they occur on

• the skin,
• the skin appendages, and
• the mucous membranes

. They are therefore fungal diseases of the skin—also known as dermatomycoses. They are usually caused by dermatophytes or yeasts.

Among the most common localized or superficial mycoses are

• athlete’s foot (tinea pedis or interdigital mycosis),
• nail fungus (tinea unguium or onchomycosis), and
• vaginal yeast infection (vaginal mycosis).

Systemic fungal infections

In a systemic fungal disease, the pathogen spreads throughout the entire body via the bloodstream. A systemic fungal infection is very rare but can be life-threatening.

Examples of systemic fungal infections include the following conditions:

• Aspergillosis (fungal infection of the skin, ears, or lungs)
• Histoplasmosis (also known as Darling’s disease; occurs in the lungs)
• Cryptococcosis (affects the lungs and meninges)
• Blastomycosis (affects the lungs and skin)

Systemic fungal infections almost exclusively affect people with weakened immune systems.

The causative agents are yeasts and molds. 

Using the DHS system, the fungi that cause infections can be divided into three different groups:

• Dermatophytes: Causative agents of 70.5 percent of all fungal infections
• Yeasts: 24.4 percent
• Molds: 5.1 percent

Classifying the causative agents is important for treatment planning.

The various fungal genera differ in terms of

• their contagiousness as well as
• the site of occurrence in the human body.

In addition, there are differences in the course of the fungal infection.

Dermatophytes

Dermatophytes are filamentous fungi. The following genera of dermatophytes are particularly common:

• Epidermophyton
• Microsporum
• Trichophyton

Dermatophytes can infect both people with weakened immune systems and healthy individuals.

They cause only superficial fungal infections, so they never affect the body’s internal organs. Accordingly, these fungi only infect the skin, toenails, fingernails, or hair.

Athlete’s foot and nail fungus are particularly common in this context. 

Yeast

Yeast fungi are also known as budding fungi. Among the most common yeast fungi are:

• Candida
• Cryptococcus
• Pityrosporum

People with weakened immune systems are particularly prone to yeast infections.

Yeast fungi can cause a localized fungal infection. It usually occurs on the skin and mucous membranes. Less commonly, it can affect the hair and nails. Yeast fungi can also cause systemic fungal infections.

Yeast fungi frequently lead to one of the following fungal infections:

• Candidiasis (especially in the mouth and throat)
• Thrush
• Vaginal yeast infection

Molds

Molds belong to the filamentous fungi. Well-known mold genera include Aspergillus and Mucor.

They usually affect only people with weakened immune systems. In such cases, they typically cause diseases of the internal organs, such as the lungs. Superficial fungal infections, such as

• the skin,
• the mucous membranes, or
• the hair

are much less commonly caused by molds.

Dermatophytes are transmitted through contact infection. A direct contact infection requires direct contact with an infected person or animal. An indirect contact infection occurs through contact with a contaminated surface.

Yeasts and molds are usually transmitted by inhaling their spores. The spores then spread throughout the body via the bloodstream. Yeasts and molds can also be transmitted through contaminated food.

Generally, the immune system can keep most fungi in check. The risk of a severe fungal infection arises only when the immune system is severely compromised. The following individuals are particularly at risk:

• Patients who have undergone major surgery, chemotherapy, or a transplant
• People who must take medications that suppress the immune system on a long-term basis, such as antibiotics or antidepressants
• People with diabetes, HIV, or circulatory disorders
• People who are severely overweight

In addition to serious illnesses, there are other risk factors:

• A moist and acidic skin environment, such as that caused by heavy sweating or a hot, humid climate. This includes the spaces between the toes and the armpits.
• Damaged skin, which makes it easier for fungi to breach the natural skin barrier
• the use of public showers, saunas, or swimming pools
• genetic predisposition

Superficial fungal infections are very common. Athlete’s foot and nail fungus are widespread conditions. According to reliable estimates, about 30 percent of the population in this country suffers from athlete’s foot. One in six Germans—or 16 percent—has nail fungus.

Vaginal yeast infections are even more common. More than three-quarters of all German women experience this condition at least once in their lives.

Systemic fungal infections, on the other hand, are extremely rare.

Causes and Symptoms of Athlete’s Foot

This skin infection is medically known as tinea pedis or interdigital mycosis. Athlete’s foot is often chronic. In most cases, dermatophytes are the causative agents. However, molds or yeasts can also trigger athlete’s foot.

Athlete’s foot usually develops in the spaces between the toes or on the sole of the foot. It is only in advanced stages that the top of the foot becomes affected.

Athlete’s foot usually manifests as severe itching between the toes. This itching persists for a long time and is typically accompanied by redness of the affected skin areas. In addition, there is increased flaking in this area of the skin. Furthermore, small pustules or blisters often appear and become inflamed.

The infected areas often have an unpleasant odor and cause pain.

You should have athlete’s foot treated immediately. Otherwise, there is a risk that this fungal infection will develop into nail fungus. 

Athlete’s foot damages the skin on the feet © chaipanya | AdobeStock

Causes and Symptoms of Toenail Fungus

Nail fungus is also known as tinea unguium, onychomycosis, or onchomycosis. It is a fungal infection of the toenails or fingernails that is often chronic. The pathogens responsible for nail fungus are usually dermatophytes. In rare cases, however, nail fungus can also be caused by yeast or mold.

Toenail fungus is usually the result of untreated athlete’s foot. Overall, it occurs more frequently than fingernail fungus.

Nail fungus gradually destroys the nail plate and, with it, the nails’ protective function.

A typical sign of a nail fungus is discoloration of the nails, such as

• whitish, yellow, or brown spots on the nail, as well as
• whitish or yellowish discoloration along the nail edge.

In addition, nail fungus is associated with

• thickening of the nail plate,
• brittle nails,
• an inflamed nail bed, and
• pain when walking or moving the fingers

.

Nail fungus causes the nails to become misshapen and discolored © Serhad | AdobeStock

Causes and Symptoms of Vaginal Yeast Infection

Medically, a vaginal yeast infection is also known as vaginal mycosis. This specific form of mucosal mycosis occurs in a woman’s genital area. It causes inflammation of the external and internal genital areas. In most cases, a vaginal yeast infection is caused by a yeast infection. The yeast Candida albicans is particularly common.

A vaginal yeast infection is characterized by severe itching in the genital area. Other symptoms include

• an unpleasant burning sensation in the vagina or the external genital area
• an increase in vaginal discharge
• swelling and redness in the genital area
• pain during sexual intercourse or urination.

Other superficial fungal infections

Other superficial fungal infections are much less common than athlete’s foot, vaginal yeast infections, and nail fungus. Examples include the following fungal infections:

• Scalp ringworm, also known as tinea capitis, which is a fungal infection of the scalp
• Tinea corporis, or ringworm of the body, which spreads across the trunk, arms, and legs
• Fungal infection of the hand, also known as tinea manus
• Fungal infection of the lower leg, also commonly referred to as tinea cruris
• Fungal infection in the groin area, also known as tinea inguinalis
• Beard ringworm, or tinea barbae
• Pityriasis versicolor
• Yeast infections, such as candidiasis or thrush

As part of the diagnostic process, the doctor determines whether a fungal infection is present and, if so, what type. This requires a three-step examination:

• Examination of the patient and review of medical history
• Collection of a smear specimen to identify the pathogen
• Preparation of a fungal culture to identify the pathogen

Medical history interview and physical examination

Typically, the dermatologist performs the patient examination. If a vaginal yeast infection is suspected, please consult a gynecologist.

First, a medical history interview takes place. A medical history refers to the documentation of the patient’s symptoms and medical history. By questioning the patient, the doctor attempts to draw conclusions about the causes of the fungal infection.

The doctor then performs a physical examination. During this examination, the doctor closely examines the areas of skin affected by the condition. The doctor usually makes the diagnosis based on the observable symptoms.

Detection of the pathogen using a fresh specimen

During the physical examination, the doctor usually also collects a fresh specimen. Medical professionals refer to a fresh, unfixed sample as a “fresh specimen.” When testing for a fungal infection, small samples of skin, nails, or dandruff serve as the fresh specimen.

The doctor then examines the specimen on a microscope slide under a microscope. If fungal elements are present, they can be seen under magnification.

However, the fresh specimen alone is not sufficient to determine the specific pathogen. To identify the pathogen, a fungal culture must be established.

Pathogen Identification Using a Fungal Culture

To determine the exact fungal pathogen, the pathogen is cultured in the laboratory. To do this, the direct smear is applied to a suitable culture medium. At the appropriate ambient temperature, the pathogens multiply and a culture develops.

After about three to four weeks, the fungal culture has grown enough to allow the pathogen to be identified.

Identifying the pathogen is necessary to tailor the treatment precisely to it. This ensures the best chances of optimal treatment success.

Antifungal agents are scientifically known as antimycotics. They effectively combat fungal infections. These active ingredients have a killing (fungicidal) or growth-inhibiting (fungistatic) effect on fungal pathogens.

In addition, antifungals are classified based on their spectrum of activity. So-called narrow-spectrum antifungals are effective only against a limited number of pathogens. Broad-spectrum antifungals, on the other hand, combat a large number of different fungal pathogens.

Therefore, knowing the specific causative pathogen is crucial for selecting the right medication.

Note: When using the prescribed antifungals, follow your doctor’s instructions exactly. Continue using the medication for the full prescribed duration—even if your symptoms have disappeared. Stopping treatment prematurely increases the risk of recurrence because any remaining pathogens can multiply again.

Antifungal medications can generally be divided into two categories:

• topical antifungals
• systemic antifungals.

Topical antifungals combat the pathogens causing a fungal infection through external application. Systemic antifungals, on the other hand, are taken orally.

Topical treatment for superficial fungal infections

Topical antifungals are intended exclusively for local, external use. Apply these antifungals directly to the affected areas of the body. Be sure to follow the instructions of your doctor or pharmacist! Topical antifungals are available over the counter as

• ointments,
• creams, or
• nail polish.

Topical treatment is recommended for fungal infections

• of the skin,
• skin appendages, and
• mucous membranes

. This is how conditions such as athlete’s foot, nail fungus, and vaginal yeast infections are treated.

Among the most commonly used topical antifungals are:

• narrow-spectrum antifungals, particularly tolnafat and nystatin, which has proven to be very effective against yeasts.
• Broad-spectrum antifungals, which include azoles such as clotrimazole and bifonazole (with additional fungicidal activity), econazole, miconazole, and ketoconazole. In addition, doctors prescribe amorolfine and terbinafine as broad-spectrum antifungals with fungicidal activity.

Serious side effects generally do not occur with topical antifungals. Possible side effects are usually limited to skin reactions, such as skin irritation. 

Systemic therapy for fungal infections inside the body

Systemic antifungals are usually administered in tablet form or as an infusion. This allows the active ingredient to be distributed throughout the entire body via the bloodstream.

The active ingredients used in systemic antifungal therapy include, in particular,

• flucytosine,
• terbinafine, and
• amphotericin B

are particularly suitable.

Systemic treatment of a fungal infection is necessary when the pathogen has spread inside the body. In some cases, a superficial fungal infection may be too advanced, or topical treatment may prove ineffective. In such cases, systemic antifungals are also used.

Other indications for the use of systemic antifungals include:

• patients who cannot tolerate topical antifungals, and
• severe skin lesions.

Your treating physician will carefully weigh the benefits and risks of systemic therapy for fungal infections.

By taking appropriate measures and following a few guidelines, you can reduce the risk of infection. The key is to

• preventing infection with a pathogen from the outset or
• preventing the fungus from spreading throughout the body.

Shared towels can be a potential route of transmission for fungal infections. Therefore, do not share your towel with others. It is also advisable to wash your towel regularly at temperatures above 60°.

Pets can carry many fungal pathogens. Have your pet examined regularly by a veterinarian. This allows a fungal infection in the animal to be detected and treated before it spreads.

Be Cautious in Public Facilities

A warm, humid environment is extremely conducive to the growth of fungal pathogens. Such environments are found in saunas, swimming pools, and communal showers. In these places, the likelihood of contaminated surfaces is very high.

In these public places, consistently avoid contact with surfaces to minimize your risk. Place a towel on seats and benches before sitting down. Be sure to wear shower shoes instead of walking barefoot. This will significantly reduce your risk of infection.

A Strong Immune System as Effective Protection Against Fungal Infections

Fungi are part of the flora that colonizes the human body. However, fungal pathogens can only multiply and cause an infection when the immune system is weakened.

A healthy immune system is therefore very important for preventing fungal and other pathogens. A healthy lifestyle directly strengthens the immune system. This includes:

• A balanced diet: plenty of fruits and vegetables and not too many carbohydrates. Carbohydrates are converted into sugar in the body. Some fungal pathogens feed on sugar.
• Regular exercise promotes blood circulation and keeps the body healthy.
• If necessary, dietary supplements can help replenish valuable minerals and vitamins in the body.

Proper personal care and hygiene

During your daily personal hygiene routine, be sure to avoid an overly moist skin environment. This is especially important for skin folds where sweat and moisture accumulate. These include

• the spaces between the toes,
• the groin area, and
• the armpits.

Always ensure good ventilation in these areas and wash regularly. After washing, be sure to dry these areas thoroughly.

Allowing the skin’s surface to dry out also increases the risk of infection. Dry skin is prone to developing fine cracks. Fungal pathogens can penetrate these cracks and then spread further.

A body wash or lotion provides moisture and nourishing oils and prevents the skin from drying out.

But don’t overdo it with personal hygiene. Washing too frequently or using harsh cleansers can disrupt the natural balance of the skin’s flora. This risk is particularly present in the female genital area.

Wearing the right clothing is also important

Wear breathable, air-permeable clothing that minimizes sweating. In addition, the following tips can help prevent a fungal infection:

• Don’t share your clothes with others
• Shoes made of breathable material help prevent nail or foot fungus
• If necessary, you can disinfect your shoes with a special spray
• Choose cotton socks and stockings and change them daily
• Wear cotton underwear, which you should also change daily
• Avoid wearing pants that are too tight