Mycology and Mycotic Diseases

Mycology

• Mycology is the study of fungi and their functions in nature.
• Fungi lack chlorophyll but have cell walls, budding structures (unicellular), filamentous structures, and produce spores.
• Medical mycology focuses on diseases caused by fungi.

Types of Mycotic Diseases

• Hypersensitivity: Allergic reaction to molds and spores.
• Mycotoxicosis: Poisoning of humans and animals by fungi toxins.
• Mycetismus: Ingestion of pre-formed fungal toxins.
• Infection: Pathogenic fungi cause infections.
• Most common pathogenic fungi do not produce toxins.

Candidiasis

• Candidiasis refers to infections caused by Candida species.
• Candida albicans is clinically important due to varying drug resistance and treatment needs across different species.

Oral Candidiasis

• Also known as moniliasis or thrush.
• Caused by the Candida albicans yeast-like fungus.

Symptoms of Oral Candidiasis

• White bumps on the tongue, cheeks, gums, or tonsils.
• Bleeding when bumps are scraped.
• Pain at the affected sites.
• Dry, cracked skin at the corners of the mouth.
• Difficulty swallowing.

Risk Factors for Oral Candidiasis

• Newborns
• Adults with diabetes
• Denture wearers
• Antibiotic or chemotherapy patients
• Drug users
• Poor nutrition
• Immune deficiency

Diagnosis of Fungal Infections

• Wet mount
• Dermal hypersensitivity
• Direct fluorescent microscopy
• Serology
• Culture and biopsy
• Molecular methods

Treatment of Fungal Infections

• One of the first chemotherapeutic agents (oral iodides) was an anti-mycotic (used in 1903)
• Developments in anti-fungal agents continue to be made.

Cryptococcosis

• Cryptococcus is a genus of fungi that grow as yeasts.
• Common manifestations include meningitis (most common) and pulmonary infections.
• Infections can be subacute or chronic.
• Meningoencephalitis caused by C. neoformans is a highly fatal condition.

Symptoms and Diagnosis of Cryptococcosis

• Initial symptoms include vision problems, lethargy, and headaches.
• Symptoms can progress to delirium, neck stiffness, coma, and death.
• Diagnosis requires a spinal tap (lumbar puncture).
• CSF examination includes characteristic chemistry, evidence of the organism (India ink preparation), and serological assays for C. neoformans antigen.
• Cause of death is often due to cerebral edema and increased intracranial pressure.
• Ecological niche is found in pigeon and chicken droppings.

Superficial Mycoses

• Fungal infections that affect the outer layers of skin, hair, and nails, not invading living tissue.
• Dermatophytes and keratinophilic fungi are the causative agents, breaking down keratin.
• Tinea refers to various forms, including:
  • Tinea corporis (ringworm).
  • Tinea pedis (athlete's foot).
  • Tinea unguium (onychomycosis)
  • Tinea capitis.
  • Tinea cruris ("jock itch").
  • Tinea barbae
  • Tinea versicolor.

Explore the fascinating world of mycology, the study of fungi and their roles in nature. This quiz covers the types of mycotic diseases, including infections caused by fungi such as Candida albicans, and highlights key symptoms of oral candidiasis. Test your knowledge on the different aspects of fungal biology and pathology.