Types of Mycoses (Fungal Infections)

Mycoses are fungal infections that affect humans and animals. They are classified based on the depth of infection, route of entry, and the part of the body affected.

1. Classification of Mycoses

A. Superficial Mycoses

• Definition: Affect only the outermost layers of the skin, hair, or nails without causing significant inflammation.
• Examples:
1. Pityriasis (Tinea) Versicolor – Caused by Malassezia furfur, results in discolored skin patches.
2. Tinea Nigra – Caused by Hortaea werneckii, results in dark brown to black patches on palms or soles.
3. Black Piedra – Caused by Piedraia hortae, forms hard black nodules on hair shafts.
4. White Piedra – Caused by Trichosporon species, forms soft white nodules on hair shafts.

B. Cutaneous Mycoses (Dermatophytoses)

• Definition: Involve the epidermis, hair, and nails, leading to inflammation.
• Causative Agents: Dermatophytes (Trichophyton, Microsporum, Epidermophyton species).
• Examples:
1. Tinea Capitis – Scalp infection (ringworm of the scalp).
2. Tinea Corporis – Infection of the body (ringworm).
3. Tinea Pedis – Athlete’s foot, affects the feet.
4. Tinea Cruris – Jock itch, affects the groin area.
5. Tinea Unguium (Onychomycosis) – Fungal nail infection.

C. Subcutaneous Mycoses

• Definition: Infections that affect deeper layers of the skin, subcutaneous tissue, and sometimes bones. They usually occur after traumatic implantation of fungi.
• Examples:
1. Sporotrichosis – Caused by Sporothrix schenckii, often called "rose gardener’s disease."
2. Chromoblastomycosis – Caused by pigmented fungi (Fonsecaea, Cladophialophora), leads to wart-like lesions.
3. Mycetoma (Madura foot) – Caused by fungi (Madurella species), results in swelling and pus discharge.
4. Lobomycosis – Caused by Lacazia loboi, leads to chronic skin infections.

D. Systemic (Deep) Mycoses

• Definition: Affect internal organs and spread via the bloodstream. They are often life-threatening, especially in immunocompromised individuals.
• Examples:
1. Histoplasmosis – Caused by Histoplasma capsulatum, affects the lungs, common in bird/bat droppings.
2. Blastomycosis – Caused by Blastomyces dermatitidis, affects the lungs and skin.
3. Coccidioidomycosis (Valley Fever) – Caused by Coccidioides immitis, found in desert soil.
4. Paracoccidioidomycosis – Caused by Paracoccidioides brasiliensis, affects the lungs and mucous membranes.

E. Opportunistic Mycoses

• Definition: Occur in immunocompromised individuals (e.g., HIV/AIDS, cancer, organ transplant patients).
• Examples:
1. Candidiasis – Caused by Candida albicans, affects the mouth (oral thrush), vagina (yeast infection), and bloodstream.
2. Aspergillosis – Caused by Aspergillus species, affects the lungs and sinuses.
3. Cryptococcosis – Caused by Cryptococcus neoformans, affects the brain and lungs.
4. Mucormycosis (Zygomycosis) – Caused by Mucor and Rhizopus species, leads to aggressive tissue destruction.
5. Pneumocystis Pneumonia (PCP) – Caused by Pneumocystis jirovecii, a serious lung infection in AIDS patients.

Mycoses range from mild, superficial infections to severe, life-threatening systemic diseases. Early diagnosis and appropriate antifungal treatment are crucial for managing fungal infections.