nomenclature and classification of mycoses superficial mycoese, all the cutaneous, sub cutaneous, systematic

nosology definitions

• classification of list of diseases

nosology of mycoses

• both name of the fungi and the names of skin diseases caused by fungi are problematic

  • there are common names/ disease names that look like Genus species but the disease could be due to anything

  • like all the candida things or the T. something for the tineas

• there are no sets of rules for disease names for fugal diseases

• or mycoses added

• or disease named after the pathogen

what suffix is added for fungal diseases? and where?

mycoses

ex. bronchomycosis, otomycosis, dermatomycosis

why is tinea confusing?

• tinea just meand ringworm and there are endless fungal infections of the skin, specific types are usually designated by modifying a term

  • tinea barbis

  • tinea capitis

  • tinea pedis

  • tinea manis

exongenous aquisition

• transmitted through airborne, cutaneous, percutaneous routes

endogenous aquisition

• may be acquired from commensals, or reactivation

virulence and fungal diseases

• primary pathogens and opportunistic pathogens

viruelnce: primary pathogens

may establish infection in an immunologically normal host

virulence: opportunistic pathogens

• requires some compromise of host defenses for infection to become established

classification of fungla infections by location

1. superficial mycoses

2. cutaneous mycoses

3. subcutaneous mycoses

4. systematic mycoses

they are not mutually exclusive!

superficial mycoses

infections limited to the outermost layers of the skin and hair

cutaneous mycoses

infections that extend deeper into the epidermis as well as invasive hair and nail diseases

• outermost protective boundary = skin

subcutaneous mycoses

infections involving the dermis sybcutaneous tissues muscle and fascia

systematic mycoses

infections that may spread to many organ systems

keratin? and keratin disease name?

• fibrous structural protein, outer layer of skin

• there is alpha an beta keratins

• onychomycosis

dermatophytes

• fungi that grow on the keratinized layers of epidermis and their appendages

• don’t usually enter living tissues

• can be pathogenic fungus that grows on skin hair feathers etc

how do dermatophytes vary by region?

• tines capitis more in developing countires

• and tinea pedis and onychoycosis

malassezia species (not dermatophytes)

• the genus is groups of yeast that are skin residents on human and warm blooded animals

• dimorphic species, lipophilic

• they are commensal and opportunistically pathogenic

• technically basidiomycetes while dermatophytes are ascomycetes

superficial mycoses

• cosmetic fungal infections, no living tissue is invaded and there is no cellular response

• most people unaware

6 superficial mycoses

1. pitytriasis versicolor Malassezia sp. common

2. dandruff Malassezia sp. common

3. seborrheic dermatitis Malassezia sp. common

4. tinea nigra rare

5. black piedra rare

6. white piedra rare

Pityriasis versiscolor (not genus species name)

• sometimes tinea versicolor

• flaky colored patches mainly chest and back

• hypo and hyper pigmentation

• in more tropical areas

dandruff

• malassezia furfur

• dead cells of skin from the scalp shedding

• saprophyte, always present just some people have a problem

• very poorly defined issue, but mostlikely due to bacterial populations change and cause an imbalance of the entire microbiome

seborrhoeic dermatitis

• mostly afects the scalp as scaly patches, red skin, dandruff

• non contagious long term condition

• probably single most common inflammatory skin condition affecting humans besides acne

tinea nigra

• on the palm or the sole with black or brown patches, don’t itch or sting

• found in soil

• dermatophytosis

white and black piedra

• infections of the scalp hairs

• nodules are concretion of hyphae and fruiting bodies

• due to different species

trichomycoses

• any diseases of the hair caused by fungi

tinea

various fungal infections of the skin, hair, or nails caused chiefly by species of the genera Microsporum, Trichophyton, and Epidermophyton

• some people think it looks like a worm

tineas are what type of mycoses?

cutaneous, dermatophytes

how are tineas usually categorized

• usually by the part of the body that is infected

  • tinea barbae

  • tinea capitis

  • tinea corporis

  • tinea cruris “jock itch”

  • tinea manus

  • tinea pedis “athletes foot”

  • tinea unguium

athletes foot: tinea pedis

• frequently occuring dermatophytosis

• spreads in warm and moist environments with close contat with other people

• usually living on the skin but will become an infection when there is another condition

tinea capitis

• balding spots on the head

tinea barbae

• follicles invaded, similar to tinea capitis

• spread through dirty razors usually

tinea manus

hand ringworm

tinea cruris

• spreads through fomites which are inanimate objects are contaminated with infectious agents

• ike towels , bedding, gym equipment

• diabetes and obesity are additional risk factors , in communal areas like military jails

• more common in men, can be spread from athletes foot

tinea unguium

• most common fungus ingection and also caused onychomycosis

ringworm is contagious, how does it spread?

• from person to person who has ringworm

• from an animal that has ringworm

• from the environment

sporotrichosis

• cutaneous disease, rose thorn disease

• it is found in soil, hay, pshagum mosss and plants it usually affects farmers or agricultural workers

  • through small cuts and abrasions in the skin to cause the infection

what is favus?

• extreme form of tinea capitis

• caused by scutula

what are things misdiagnosesd as ringworms?

• cradle cap, seborrheic dermatitis

• diaper rash

• trench foot

major types of subcutaneous mycoses

• chromoblastomycosis

• mycotic mycetoma

• sporotrichosis

• lobomycosis

• subucanteous zygomycosis

subcutaneous mycosis

• pathogen penetrates the dermis or even deeper after a skin trauma, can become systematic

• a lot are caused by dark walled fungi

chromoblastomycosis

• long term fungal infection of the skin and subcutaneous tissue

• most common in tropical or subtropical climates, rural areas especially

• rarely fatal, slow growing, difficult to cure

• thought to originate from minor trauma to the skin

• fpnseca’s disease or pedroso’s disease

mycetoma general time

• chronic, inflammatory swellings with numerous sinuses

• madura foot

sporotrichosis

• caused by the mould sporothrix schenckii

• dimoprhic 37C and on rich nutrient the yeast phase occurs

• at 25C asexual form occurs

lobomycosis

• kelloidal blastomycosis

• common in native/ indegnous groups

• incredibly painful

zygomycosis

• generic term for disease caused by members of this taxonomic group

• mucormycosis is an alternate name

• saprophytic fungi that are in soil or vegetation some can become systemic

dimorphism

• two forms, many medically important fungi also have two forms, as yeasts and mold

• temperature dependent alterations in morphological state

• often exist as nonvirulent filamentous form

Body Heat Probably (Changes) Shape

blastomyces dermatitidis

Histoplasma capsulatum

Paracoccidoides immitis

Sporothrix schenckii

mold in the cold yeast in the heat

• the fungi are pathogens at 37C

innate immune system

• provides an immediate non speciic response

• pathogen associated immunostimulents

• is central host defenses against fungi

adaptive immune system

• activated by innate response

• responds and recognizes the pathogen

immunodeficiency

primary:

secondary: leukemia, chemotherapy, AIDS, malnutrition

neutropenia

abnormally low concentration of neutrophils in the blood

fungemia

• is the presence of fungi in the blood

systemic mycoses

• the fungi can then spread via the bloodstream to multiple organs including the skin often causing multiple organs to fail

• results in death

• te state of the immune system is the most imporntat factor of the illness

opportunistic infection

• aspergillosis

• candidiasis

• cryptococcosis

• penicilliois

• zygomycosis

what are thefour ost common systemic human fungal pathogens

1. aspergillus fumigatus mold

2. candida albicans (yeast) single most common

3. cryptococcus neoformans (dimorphic)

4. pneumocytosis jirovecii (cant be cultured)

aspergillosis

• healthy immune systems deal effectively with inhaled spores, opportunistic pathogen

• for some workers if their occupation exposed to massive spore concetrations even healthy respitory defenses are overwhelmed

• free living sapribes, 300 species but aspergillus fumigatus is the most common, then flavus, then niger

• called invasive when it is systematic, and called the disease of the diseased

candidiasis

• infection and allergic reactions, bunch of species but five main ones causing 90% of illnesses

• thrush, yeast infection

• its pleomorphic because both are present, the filmentous hyphae are better at penetrating, pathogenic, resistant

• candida albicans main

candidemia

• yeast infection in bloodstream

cryptococcus

• neoformans causes cryptococcis and is most medically important

  • africa and australia

• causes diseas in nonimmunocompormised peopl too

• most life threatening for people with aids

• connected with pigeon poop

pneumocytic jirovecii

• causes cysts, deadly in hiv/ aids people

penicillium marneffei

• penicilliosis one rare increase occurence due to aids or hiv positive people