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Superficial Mycoses

Fungi Pathophysiology

Fungi are eukaryotic, aerobic organisms

Can reproduce sexually and asexually

Only 100 species are important in human disease

Represents <0.05% of total species number

Most fungi exist as saprophytes ringworm tinea

Infections are usually acquired from fungi in the environment

Dermatophytoses ringworm tinea Mycoses

Yeast infections

Nigra Piedra

Superficial: Pathogenesis

Grows in stratum corneum or in/on hair shafts

Host conditions needed for growth: micro trauma

Increased hydration

Occlusion

Increased temperature

Pathogenesis

Stages of infection

Incubation

Refractory period

Involution

Immunology

Nonimmunologic resistance

Fungistatic/cidal fatty acids on the skin - serum inhibitory factor (eg, transferrin)

Immunologic resistance

Type IV delayed-hypersensitivity

Humoral immunity