Superficial and Cutaneous Mycoses

Question 1

What causes mycoses

Answer 1

Yeasts for the most part

Question 2

What causes Pityriasis Versicolor

Answer 2

Malassezia Furfur

Question 3

What does Pityriasis Versicolor look like

Answer 3

Hypo or hyper pigmented macules on chest, neck, back

Question 4

What immune responses do we typically see to Superficial Mycoses?

Answer 4

Little to no immune response

Question 5

Where do superficial mycoses colonize?

Answer 5

Outer keratinized surface of skin, hair, or nails

Question 6

What causes dandruff?

Answer 6

Malessezia Globosa

Question 7

How do we diagnose a superficial mycosis?

Answer 7

Direct visualization of yeast-like cells and short branched pseudohyphae.

Question 8

Treatment for superficial mycosis?

Answer 8

Topical therapy, olive oil, single dose oral azole if widespread

Question 9

What makes a cutaneous mycosis different from a superficial one BASICALLY?

Answer 9

Cutaneous involves invasion of the epidermis with an inflammatory response. They break down keratin after invading the stratum corneum.

Question 10

What primarily causes cutaneous mycoses?

Answer 10

Mold dermatophytes such as trichophyton, epidermophyton, and microsporum

Question 11

What does microsporum typically cause?

Answer 11

Athlete’s foot, jock itch, ringworm

Question 12

Tinea infections

Answer 12

Latin for “worm”

Caused by dermatophytes. Result in inflammatory scaling often in the pattern of an expanding circle or ring with frequent hair loss

Question 13

Tinea capitis

Answer 13

Tinea infection of the head

Question 14

Tinea Coporis

Answer 14

Trunk of the body

Question 15

Tinea Barbae

Answer 15

Tinea of the face

Question 16

Tinea Cruris

Answer 16

Tinea inguinally

Question 17

Tinea pedis

Answer 17

Tinea of the foot

Question 18

Normal treatment for tinea?

Answer 18

Topical anti-fungal treatment. When hair or nails are involved, oral antifungal treatment is usually necessary.

Question 19

How do we diagnose Tinea?

Answer 19

Microscopy/culture

Question 20

Subcutaneous Mycoses

Answer 20

Invade the subcutaneous fat. This is rare, usually induced by trauma and often has a slow progression requiring surgery.

Question 21

Spreading pattern of subcutaneous Mycosis

Answer 21

Laterally, not to distant organs

Question 22

Sprotrichosis is caused by what

Answer 22

sporothrix schenckii transmission. This is a dimorphic fungi found in soil and vegetation. Penetrated epidermis will permit growth via a yeast form of this.

Question 23

Symptoms of a sprotrichosis mycosis infection

Answer 23

Usually starts as a small nodule that ulcerates and becomes painful. 2-3 weeks later secondary lesions along lymphatics progress proximally (sporotrichoid spread- other diseases exhibit a similar “spread”).

Question 24

Diagnosis of Sprotrichosis mycosis

Answer 24

Biopsy. Can establish genus and species from culture

Question 25

Treatment of Sprotrichosis Mycosis

Answer 25

Intraconazole orally - can take several weeks

Question 26

How do we typically get Sprotrichosis mycoses?

Answer 26

Inhalation typically

Question 27

Chromomycosis

Answer 27

Found in the tropics, this is an opportunistic fungus

Question 28

What is a granulomatous infection?

Answer 28

Result of an opportunistic subcutaneous fungal infection. They emerge out from the subcutaenous tissue and emerge outward. They form medlar bodies

Question 29

How do we treat subcutaneous mycoses?

Answer 29

Very difficult, usually try azoles long term

Question 30

Eumycotic mycetoma

Answer 30

Caused by a variety of fungi in the soil entering wounds. Causes a deep subcutaneous fungal infection that results in gross localized swelling with underlying sinus tracts. Granulomas can develop with granule formation and pus

Question 31

Fungi that can cause Eumycotic mycetoma

Answer 31

``` Madurella (most common) Fusarium Acremonium Exophiala Scedosporium ```

Question 32

What eumycotic mycetoma do we find in trench warfare?

Answer 32

Madurella

Question 33

How do we diagnose Eumycotic mycetoma

Answer 33

Detection of granules by gross visualization or microscopy

Question 34

How do we treat Eumycotic mycetoma

Answer 34

Antifungal agents and local surgery. Treatment is usually not effective. Frequent cure is amputation

Question 35

Discuss microscopy as it is used to diagnose fungal infections: 10% KOH Tests

Answer 35

10% KOH tests are typically done on skin scraping. If you think cutaneous fungal infection, you may do this. KOH dissolves away keratinocytes and you may see fungal elements

Question 36

Discuss microscopy as it is used to diagnose fungal infections: Calcofluor white

Answer 36

Calcofluor white (generally a go to stain) is a fluorescent dye which binds to fungal walls

Question 37

Discuss microscopy as it is used to diagnose fungal infections: India Ink

Answer 37

o India ink (not as popular) used on CSF to look for Cryptococcus (has a large suger capsule. It shows as a halo under india ink

Question 38

Discuss microscopy as it is used to diagnose fungal infections: Methenamine Silver

Answer 38

There are a number of silver stains. This is fairly popular.

Question 39

Why is culture is considered the gold standard for detecting fungi

Answer 39

1. More sensitive than microscopy 2. Allows for ID via mycelium appearance or presence of asexual spores (genus and species) 3. Usually grown on Sabouraud’s agar – designed to inhibit bacterial growth 4. Most fungi can grow in standard blood culture bottles

Question 40

What is mycology

Answer 40

Study of fungi

Question 41

What type of organism is a fungus?

Answer 41

Fungi are eukaryotic, uni or multicellular, non-photosynthetic, and have chitin and glucan cell walls.

Question 42

What is a good medicinal target structurally on the fungus?

Answer 42

Fungal membrane contains ergosterol (mammal cell walls contain cholesterol so ergosterol is a good medicinal target

Question 43

Different types of general fungi?

Answer 43

They consist of yeasts (unicellular), molds (multicellular), or can be both (dimorphic).

Question 44

Are fungi aerobic or anaerobic?

Answer 44

Aerobic typically

Question 45

How do yeast multiply

Answer 45

Binary Fission | Budding (typically the route they take)

Question 46

What are hyphae and where do we find them?

Answer 46

Molds grow apically and branch via hypae (branches). At the hyphae, molds can grow spores.

Question 47

What are septa and where do we find them?

Answer 47

Hyphae have septa that have pores that allow communication and nutients vs. discrete cells.

Question 48

How do fungal spores reproduce?

Answer 48

Most fungal spores reproduce through mitosis (asexual) although some are sexual and reproduce via meiosis.

Question 49

Can Neutrophils combat fungi? If so how?

Answer 49

Neutrophils fight extracellular molds such as aspergillus and release defensins to fight them