Fungal infections, also known as mycoses, are very common and can affect people of all ages. Although they can occur on the skin, nails, hair, and mucous membranes throughout the body, some areas are more prone to fungal growth than others.
Skin Fungal Infections
The skin is the largest organ of the human body and often the first area to be affected by fungal overgrowth. Fungi thrive in warm, moist environments and areas that receive little airflow. As a result, some of the most common fungal skin infections include:
- Athlete’s foot (tinea pedis) – Affecting the feet, especially between the toes
- Jock itch (tinea cruris) – Occurring in the groin and inner thighs
- Ringworm (tinea corporis) – Circular rashes on the arms, legs, torso, or face
- Nail infections (onychomycosis) – Discoloration, thickening, and separation of the toenails or fingernails
While athlete’s foot and jock itch typically result from the Trichophyton rubrum dermatophyte, other fungi like Epidermophyton floccosum and Trichophyton mentagrophytes are also common causes of ringworm. Yeasts such as Candida can also lead to skin infections in various body folds.
Vaginal Yeast Infections
After the skin, the next most common site of fungal growth is the vagina. In fact, it’s estimated that nearly 75% of women will have at least one yeast infection during their lifetime. Candida albicans is the culprit behind most vaginal yeast infections.
Normally, Candida exists in small numbers in the vagina and is kept in check by healthy bacteria. However, when the environment changes due to antibiotic use, hormonal fluctuations, impaired immunity, and increased pH, Candida is able to overgrow. Symptoms include vaginal itching, burning, irritation, and discharge.
Table of Common Vaginal Infection Symptoms
| Symptom | Description |
|---|---|
| Itching | Burning, irritated itching of the vulva and vaginal opening |
| Burning | Burning discomfort during urination and intercourse |
| Irritation | Swelling, redness and soreness |
| Discharge | Thick, white, curd-like discharge |
While easily treatable with antifungal medications, vaginal yeast infections can recur if the underlying cause is not addressed.
Oral Thrush
Oral thrush is a common fungal infection that occurs in the mucous membranes of the mouth and tongue. It is also caused by an overgrowth of Candida albicans and is most frequently seen in newborns, the elderly, and immunocompromised individuals.
Areas of the mouth may appear reddened or glossy and tiny white spots resembling cottage cheese typically coat the tongue, inner cheeks, gums, tonsils, and roof of the mouth. Oral thrush can spread to the esophagus if left untreated.
Risk Factors for Oral Thrush
- Impaired immune system
- Diabetes
- HIV/AIDS
- Nutrient deficiencies
- Dry mouth
- Dentures
- Inhaled corticosteroids
- Antibiotic use
Oral thrush causes discomfort or difficulty swallowing. While it can often be prevented with proper oral hygiene, medications like antifungal mouth rinses, lozenges, or tablets are typically needed to resolve infections.
Foot Fungal Infections
The feet host a wide variety of fungal infections. As one of the most common body parts to be affected, fungal foot infections account for up to 15% of skin diseases. The most prevalent foot fungus is athlete’s foot, which represents over two-thirds of tinea pedis infections.
Athlete’s foot thrives in damp areas like swimming pools, locker rooms, and shower floors. Symptoms often start between the toes before spreading to the soles and tops of the feet. In addition to itching, burning, stinging, and redness, the skin may become dry and scaly or covered in blisters and peeling.
Other fungal infections of the foot include:
- Tinea unguium – Fungal infection of the toenails
- Tinea barbae – Fungal infection of the beard area
- Tinea manuum – Fungal infection of the hands
- Tinea corporis – Ringworm of the body that spreads to the feet
Proper hygiene, keeping feet dry, wearing clean socks and shoes, and using antifungal powders and sprays can help treat and prevent fungal infections on the feet.
Genital Fungal Infections
Yeast infections can occur in both men and women in the genital area. The groin, upper thighs, penis, scrotum, and buttocks are prime targets for fungal growth.
Jock itch, also known as tinea cruris, accounts for a majority of male yeast infections. It thrives in warm, moist areas and typically results in itchy, red, ring-shaped rashes in the folds of the groin. Jock itch can be transmitted through skin contact or sharing towels, clothing or bedding.
Other genital fungal infections in men include:
- Balanitis – Inflammation of the glans (head) of the penis
- Balanoposthitis – Inflammation of both the glans and foreskin
- Candidal balanitis – Yeast infection of the glans
Genital fungal infections are less common in women than vaginal yeast infections. However, vulvovaginal candidiasis can sometimes occur along with symptoms of itching, burning, and reddened skin in the vulva and surrounding areas.
Gastrointestinal Fungal Infections
The gastrointestinal tract contains a delicate balance of microorganisms. When this microbial balance is disturbed, normally benign fungi like Candida can thrive and cause infection.
Some examples of fungal infections impacting the digestive system include:
- Oral thrush
- Esophageal thrush
- Candidiasis enteritis – Infection of the small intestine
- Fungal diarrhea
Those at greatest risk for fungal gastrointestinal infections include infants, the critically ill, people with HIV/AIDS, cancer patients, and those taking antibiotics. Symptoms can range from oral lesions and difficulty swallowing to abdominal pain, nausea, and diarrhea.
Antifungal medications are used to treat fungal infections occurring in the esophagus, stomach, and intestines. Supporting the growth of healthy bacteria through diet and supplements may also help prevent fungal GI infections.
Respiratory Fungal Infections
While less common than other areas, fungal infections can sometimes occur in the respiratory tract. This is most likely to happen in people with compromised immune systems and underlying lung disease.
Types of fungal infections impacting the lungs and airways include:
- Aspergillosis – Caused by Aspergillus fungi
- Cryptococcosis – Caused by Cryptococcus neoformans fungi
- Pneumocystis pneumonia (PCP) – Caused by Pneumocystis jirovecii fungi
- Histoplasmosis – Caused by Histoplasma capsulatum fungus
- Coccidioidomycosis – Caused by Coccidioides fungus
Those with HIV/AIDS, COPD, pulmonary fibrosis, and other lung diseases have an increased risk of developing fungal pneumonia and other respiratory mycoses. Symptoms often resemble other respiratory infections and include cough, shortness of breath, fever, night sweats, and chest pain.
Hospitalization is frequently required for treatment, which typically involves IV antifungal medications. Those with weakened immune systems may need to take antifungal drugs long term to prevent recurrence.
Table of Common Fungal Respiratory Infections
| Infection | Fungus | High Risk Groups |
|---|---|---|
| Aspergillosis | Aspergillus | COPD, immunosuppressed |
| Cryptococcosis | Cryptococcus neoformans | HIV/AIDS, immunosuppressed |
| Pneumocystis pneumonia (PCP) | Pneumocystis jirovecii | HIV/AIDS, immunosuppressed |
| Histoplasmosis | Histoplasma capsulatum | Immunosuppressed, travelers |
| Coccidioidomycosis | Coccidioides | Immunosuppressed, travelers |
Fungal Infections of the Nails
Also called onychomycosis, fungal infections of the nails are difficult to treat and can be easily spread. Toenails are about three times more likely to be affected than fingernails since they are frequently confined to dark, damp shoes and socks.
Onychomycosis accounts for approximately 50% of all nail disorders. Risk factors include:
- Athlete’s foot
- Aging
- Diabetes
- Psoriasis
- Weakened immunity
- Injuries to the nail
- Poor circulation
Initial symptoms involve the nail plate thickening and developing white, yellow, or brown discoloration. As the infection worsens, nails can become brittle and crumbly and may separate from the nail bed.
Prescription antifungal medications are frequently required to clear nail fungal infections. Topical solutions, creams, nail polish, and nail removal may also be necessary for treatment.
Fungal Infections of the Scalp
Fungal infections of the scalp, while not as common as other areas, can be difficult to treat. Scalp ringworm, known as tinea capitis, is most prevalent in children.
Some symptoms of scalp fungal infections include:
- Itchy, red, scaling patches on the scalp
- Brittle hair that breaks easily
- Dry, crusty bald spots
- Pus-filled blisters
- Hair loss
In addition to ringworm, other fungal infections like seborrheic dermatitis can also affect the scalp. Antifungal shampoos, creams, and oral medications help treat fungal scalp infections. Keeping the scalp clean and dry is key for prevention.
Table of Common Scalp Fungal Infections
| Infection | Symptoms |
|---|---|
| Tinea capitis | Scaly patches, brittle hair, bald spots, itching |
| Seborrheic dermatitis | Flaky, yellow crust on scalp, itching, redness |
| Folliculitis | Pus-filled bumps, crusting, pain |
What Body Part Has the Highest Fungal Infection Rate?
After reviewing common fungal infections throughout the body, what area has the highest rate of infections? The clear answer is the feet.
Athlete’s foot and fungal toenail infections affect up to one in five adults. The feet provide a warm, dark environment perfect for fungi to grow. The constant exposure to moisture from sweat, swimming, shoes, and socks also increases infection risk.
Genital yeast infections and fungal skin infections like ringworm are also very prevalent. However, overall, the feet have the highest percentage of fungal infections.
Some important tips to prevent foot fungal infections include:
- Washing and drying feet thoroughly, especially between the toes
- Avoid walking barefoot in public areas
- Changing socks frequently
- Wearing breathable shoes and rotating pairs
- Using antifungal foot powder
- Disinfecting pedicure tools properly
- Avoiding sharing shoes or socks with others
Practicing good foot hygiene and keeping feet clean and dry are vital for stopping fungal infections before they start. If infections develop, using antifungal creams and sprays as early as possible provides the best chance of rapid treatment and preventing spreading to the toenails.
Conclusion
Fungal infections can develop anywhere in the body but thrive in warm, moist environments. The feet are the most common site of fungal infections, with up to 15% of skin diseases occurring from athlete’s foot, toenail fungus, and other foot fungi.
Genital areas, nailbeds, and skin folds also support fungal growth but not to the same extent as the feet. Paying special attention to foot hygiene by washing and drying thoroughly, wearing clean socks, alternating shoes, and applying antifungal powders are the best ways to prevent fungal infections from taking hold.
If infections develop, over-the-counter antifungals can treat mild symptoms. However, prescription oral or topical antifungals are often needed for more severe or resistant fungal infections of the feet. Keeping feet clean, dry and fungus-free promotes good overall health.