Clinical Groupings for Fungal Infections Dr.Kedar Karki The following clinical groupings may be recognized: Skin Mycology The Superficial Mycoses These are superficial cosmetic fungal infections of the skin or hair shaft. No living tissue is invaded and there is no cellular response from the host. Essentially no pathological changes are elicited. These infections are often so innocuous that patients are often unaware of their condition. Disease Pityriasis versicolor Seborrhoeic dermatitis including Dandruff and Follicular pityriasis Tinea nigra White piedra Black piedra Causative organisms Malassezia furfur (a lipophilic yeast) Exophiala werneckii Trichosporon beigelii Piedraia hortae Incidence Common Rare Common Rare The Cutaneous Mycoses These are superficial fungal infections of the skin, hair or nails. No living tissue is invaded, however a variety of pathological changes occur in the host because of the presence of the infectious agent and its metabolic products. Disease Dermatophytosis Ringworm of the scalp, glabrous skin and nails. Candidiasis of skin, mucous membranes and nails. Causative organisms Incidence Dermatophytes (Microsporum, Trichophyton, Epidermophyton) Common Candida albicans and related species. Non-dermatophyte moulds Hendersonula toruloidea Scytalidium hyalium Scopulariopsis brevicaulis Common Dermatomycosis Rare The Subcutaneous Mycoses These are chronic, localized infections of the skin and subcutaneous tissue following the traumatic implantation of the aetiologic agent. The causative fungi are all soil saprophytes of regional epidemiology whose ability to adapt to the tissue environment and elicit disease is extremely variable. Disease Sporotrichosis Chromoblastomycosis Causative organisms Sporothrix schenckii Fonsecaea, Cladosporium etc. Phialophora, Incidence Rare Rare Phaeohyphomycosis Cladosporium, Exophiala, Wangiella, Bipolaris, Rare Exserohilum, Curvularia Pseudallescheria, Madurella, Acremonium, Exophiala etc. ranarum Rare Rare Mycotic mycetoma Subcutaneous zygomycosis Basidiobolus (Entomophthoromycosis) Conidiobolus coronatus Subcutaneous zygomycosis Rhizopus, Mucor, Rhizomucor, Rare (Mucormycosis) Absidia, Saksenaea etc. Rhinosporidiosis Lobomycosis Rhinosporidium seeberi Loboa loboi Rare Rare Infectious Disease Mycology Dimorphic Systemic Mycoses These are fungal infections of the body caused by dimorphic fungal pathogens which can overcome the physiological and cellular defences of the normal human host by changing their morphological form. They are geographically restricted and the primary site of infection is usually pulmonary, following the inhalation of conidia. Disease Histoplasmosis Coccidioidomycosis Blastomycosis khari disease Paracoccidioidomycosis Aspergillosis Penicilliumioses Degnal disease *more common in endemic areas. Opportunistic Systemic Mycoses Causative organisms Histoplasma capsulatum Coccidioides immitis Blastomyces dermatitidis Paracoccidioides brasiliensis Aspergillos spp Penocillium spp Fusarium spp Incidence Rare* Rare* Rare* Rare* common common common These are fungal infections of the body which occur almost exclusively in debilitated patients whose normal defence mechanisms are impaired. The organisms involved are cosmopolitan fungi which have a very low inherent virulence. The increased incidence of these infections and the diversity of fungi causing them, has parallelled the emergence of AIDS, more aggressive cancer and post-transplantation chemotherapy and the use of antibiotics, cytotoxins, immunosuppressives, corticosteroids and other macro disruptive procedures that result in lowered resistance of the host. Disease Candidiasis Cryptococcosis Aspergillosis Pseudallescheriasis Zygomycosis (Mucormycosis) Hyalohyphomycosis Causative organisms Candida albicans and related species. Cryptococcus neoformans Aspergillus fumigatus etc. Pseudallescheria boydii Rhizopus, Mucor, Rhizomucor, Absidia etc. Penicillium, Paecilomyces, Beauveria, Fusarium, Scopulariopsis etc. Cladosporium, Exophiala, Wangiella, Bipolaris, Exserohilum, Curvularia. Incidence Common Rare/Common common Rare common common Phaeohyphomycosis Rare