06-Superficial Fungi I Flashcards
1
Q
- Above what level of the hair shaft do dermatophytes infect?
A
- Adamson’s fringe
2
Q
- Do candida infections occur in high or low pH? What factors affect the pH conducive to candiasis?
A
- High pH; panty-liners, diapers, occlusive agents
3
Q
- What is the most reliable test to distinguish T. rubrum from T. mentag?
A
- Hair perforation test
4
Q
- Which dermatophyte is most commonly responsible for tinea gladiatorum?
A
- T. tonsurans
5
Q
- What is the causative non-dermatophyte in resistant T. Pedis?
A
- Scytalidium dimidiatum – resistant to most antifungals but sensitive to cycloheximide
6
Q
- What organism most commonly causes favus?
A
- T.schoenleilli
7
Q
- Define mycelium.
A
- A mass of hyphae
8
Q
- What are chlamydoconidia? What organism produces chlamydoconidia?
A
- Thick-walled round cells resistant to the environment. T. tonsurans
9
Q
- What is the most common cause of white superficial onychomycosis?
A
- T. mentographytes
10
Q
- What accounts for the depigmentation seen in tinea versicolor?
A
- Dicarboxylic acid
11
Q
- What is the organism responsible for tinea nigra?
A
- Horteae/ Exophiala wernickii
12
Q
- What causes black piedra? What is the clinical presentation?
A
- Piedra hortae; brown/black firmly adherent nodules on hair
13
Q
- Malassezia has been implicated in what neonatal skin condition?
A
- Neonatal cephalic pustulosis
14
Q
- Name 4 geophilic organisms. What kind of inflammatory response do they elicit in humans?
A
- M. gypseum (tinea corporis, capitis), T. terrestre, M. fulvum, M. cookie; modsevere inflammation
15
Q
- Name zoophilic organisms. What kind of inflammatory response do they elicit in humans?
A
- M. canis, T. Mentagrophytes, M. gallinae, T. equinum, T. verrucosum, M. nanum, T. simii, M. persicolor; intense inflammation
16
Q
- What are the nutritional requirements for T. verrucosum?
A
- Inositol and thiamine.
17
Q
- Which dermatophyte requires niacin for its growth?
A
- T. equinum
18
Q
- How are arthroconidia formed?
A
- By fragmentation of hyphae
19
Q
- What are sporangia?
A
- Spores that are produced in a sac
20
Q
- What are conidia?
A
- Asexual, nonmotile spores, reproductive structures
21
Q
- In which two groups of dermatophytes are macroconidia important?
A
- Microsporum and Epidermophyton
22
Q
- Name endothrix organisms.
A
- T. tonsurans, T. rubrum, T. violaceum. T. soudanense, T. gourvilli, T. yaoudei, T. schoenleinii “say say violet you’re going right to town)
23
Q
- Name ectothrix organisms.
A
- M. canis, M. audouini, M. distortum, M. ferrugineum, M. gypseum, M. distortum, T. rubrum (sometimes)
24
Q
- What causes tinea imbricata?
A
- T. concentricum
25
Q
- What causes bullous tinea?
A
- T. mentographytes
26
Q
- What is the most common cause of white superficial onychomycosis in the HIV population?
A
- T. rubrum
27
Q
- What time period does congenital candidiasis clinically present?
A
- Usually at birth, but can be up to 6 days of life
28
Q
- What is the clinical distribution of neonatal candidiasis?
A
- Diaper area and oral mucosa
29
Q
- What does AEPCED stand for and what is the gene mutation?
A
- Autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy syndrome, APECED- autosomal recessive AIRE gene
30
Q
- What is the gold standard treatment for systemic candidiasis?
A
- Amphotericin B
31
Q
- What is Jacquet’s erosive dermatitis?
A
- An erosive variant of granuloma gluteale infantum (pseudoverrucous papules/nodules in chronic irritant dermatitis)
32
Q
- What is geotrichosis and where is it normally found?
A
- Yeast-like fungus; normal flora in milk, fruit tomatoes and soil
