Fungal Infections

Fungal Infections: Causes and Treatments

Different types of fungi can cause fungal infections. In some cases, fungi that are not typically found on or inside your body can cause an infection. Sometimes, fungi that are normally present on or inside your body can grow out of control and cause an infection.

Fungal infections may be contagious. They can spread from one person to another. In some cases, you can also catch disease-causing fungi from infected animals or contaminated soil or surfaces.

If you develop signs or symptoms of a fungal infection, make an appointment with your healthcare provider. Early diagnosis and treatment are important to stop it from spreading.

What are fungal infections?

Fungal infections, also known as mycoses, are infections caused by fungi. Fungi are a group of microorganisms that include yeasts, molds, and mushrooms. While many fungi are harmless and even beneficial, some can cause infections in humans, particularly when your immune system is weakened.

Some common types of fungal infections include:

  • Athlete’s foot (tinea pedis): affects the feet, particularly between the toes
  • Ringworm (tinea corporis): causes ring-shaped rashes on various parts of the body
  • Jock itch (tinea cruris): affects the groin area
  • Candidiasis: caused by Candida species; affects the mouth (oral thrush), genital area (yeast infection), and other moist skin areas
  • Systemic infections: fungi infecting blood, lungs, or other organs
  • Opportunistic infections: occur in people with weakened immunity (HIV/AIDS, cancer treatment, organ transplant)

What causes fungal infections?

The specific cause depends on the type of fungal infection. Common risk factors include:

  • Environmental exposure: contact with contaminated soil, water, air, or surfaces
  • Contact with infected people or animals: direct contact or sharing contaminated items (towels, clothing, grooming tools)
  • Compromised immune system: due to HIV/AIDS, diabetes, cancer, immunosuppressive therapies
  • Warm and moist environments: encourage fungal growth (e.g., sweaty feet, skin folds)
  • Antibiotic use: disrupts normal bacterial balance, allowing fungal overgrowth
  • Underlying health conditions: diabetes, obesity, circulatory problems
  • Injury or trauma: cuts or punctures can introduce fungi beneath the skin

What are the types of fungal infections?

Superficial infections

Affect outer layers of skin, hair, and nails:

  • Tinea pedis (athlete’s foot)
  • Tinea corporis (ringworm)
  • Tinea cruris (jock itch)
  • Tinea capitis (scalp, with hair loss and scaling)
  • Tinea unguium (onychomycosis, nail thickening and discoloration)
  • Candidiasis (moist areas: oral thrush, vaginal yeast infection, intertrigo, diaper rash)

Subcutaneous infections

Occur beneath the skin, often after trauma:

  • Sporotrichosis
  • Chromoblastomycosis
  • Mycetoma

Deep infections

Affect major organs; can be life-threatening:

  • Histoplasmosis (lungs and other organs)
  • Coccidioidomycosis (Valley fever, primarily lungs)
  • Blastomycosis (lungs, skin, bones)
  • Cryptococcosis (lungs, spinal cord, brain)
  • Aspergillosis (lung infections)
  • Pneumocystis pneumonia (PCP, lungs in HIV/AIDS)
  • Mucormycosis (sinuses, intestines, brain, lungs)

How are fungal infections diagnosed?

  • Medical history: symptoms duration, exposures, underlying conditions
  • Physical exam: inspection of rashes, blisters, scaling, redness
  • Culture: skin scrapings, hair or nail samples, or bodily fluids for lab identification
  • Imaging tests: X-rays, CT scans, or MRIs for suspected deep or organ-based infections

How are fungal infections treated?

Treatment varies by type, location, and severity:

Topical antifungals

  • Clotrimazole (Lotrimin)
  • Miconazole (Micatin)
  • Terbinafine (Lamisil)
  • Ketoconazole (Nizoral)
  • Econazole (Spectazole)
  • Ciclopirox nail lacquer (Penlac)

Oral antifungals

  • Fluconazole (Diflucan)
  • Itraconazole (Sporanox)
  • Terbinafine (Lamisil)
  • Griseofulvin (Fulvicin)
  • Nystatin (Mycostatin)
  • Posaconazole (Noxafil) and voriconazole (Vfend)

Intravenous antifungals

  • Amphotericin B (Ambisome)
  • Caspofungin (Cancidas), micafungin (Mycamine), anidulafungin (Eraxis)
  • Fluconazole, voriconazole, posaconazole for severe cases

Other therapies

  • Surgical debridement of infected tissue
  • Drainage of abscesses
  • Combination antifungal regimens for resistant infections

How can you prevent fungal infections?

  • Maintain good hygiene: wash and dry thoroughly, especially skin folds and between toes
  • Avoid sharing personal items: towels, clothing, grooming tools
  • Wear breathable footwear and alternate shoes to allow drying
  • Use loose, breathable clothing and trim nails regularly
  • Keep cuts and scrapes clean and covered
  • Manage blood sugar if diabetic and maintain a healthy diet
  • Limit exposure to contaminated soil or water; wear protective gear
  • Use antifungal prophylaxis if at high risk (immunosuppressed)
  • Have regular check-ups if you have a weakened immune system

Sources

  • Fungal diseases. National Institute of Allergy and Infectious Diseases. Accessed May 22, 2024.
  • Lionakis MS, Edwards JE Jr. Pathogenesis, Diagnosis, and Treatment of Fungal Infections. In: Harrison’s Principles of Internal Medicine. 21st ed. McGraw Hill; 2022. Accessed May 22, 2024.
  • Fungal Diseases. U.S. Centers for Disease Control and Prevention. Accessed May 22, 2024.
  • Fungus Infections: Preventing Recurrence. American Osteopathic College of Dermatology. Accessed May 22, 2024.