Week 2 Fungal Infections- Purnuske

Question 1

Mold vs yeast

Answer 1

Mold= multicellular, form hyphae, usually produce spores
yeast= unicellular

Question 2

Cutaneous fungal infections

Answer 2

Tinea versicolor (Malassezia)
Various Tinea (dermatophytes)

Question 3

Why do dermatophytes only cause cutaneous infections?

Answer 3

• grows best at 25 degrees (interal body temp is too hot)

- requires keratin for growth so restricted to hair, nails, and superficial skin

Question 4

Microsporum

Answer 4

-Dermatophyte
-Microsporum Canis= from cats/dogs
-Microsporum Fulvum = from soild
Diagonosis: Wood’s light blue green
-Spindle shape macroconidia

Question 5

Epidermophyton floccosum

Answer 5

-dermatophyte

tinea cruris, tinea pedis, spreads through humans

Question 6

Trichophyton rubrum

Answer 6

• dematophyte

- most common cause of tinea pedis, passed between humans, moist areas of skin, transferred at swimming pools

Question 7

Trichophyton tonsurans

Answer 7

-dermatophyte

MOST COMMON CAUSE OF TINEA CAPITIS in children

Question 8

Subcutaneous fungal infection

Answer 8

infection through skin followed by subcutaneous and/or lymphatic spread

Question 9

Sporathrix

Answer 9

-subcutaneous infection
-rose gradener’s disease
-spreads through lympthatic vessels
-rare, occurs in immunocompromised patients
Treatment= intraconazole

Question 10

Opportunistic mycoses

Answer 10

normal flora infections, happen with immune deficiencies or overgrowth

Question 11

Candida albicans

Answer 11

-YEAST FORM
-diaper dermatitis, corners of mouth, toenail or edge of nails, oropharyngeal (thrush)
Treatment= keep skin dry, clotrimazole or other azole cream

Question 12

What methods are used to diagnose a fungal infection?

Answer 12

collect skin, nail, or hair with scraping
KOH dissolves human tissues can add stain and view

• wood’s lamp under which some fungi fluoresce
• PCR
• Culture (but takes a long time to grow)

Question 13

What fungus causes hypo or hyperpigmentation? How would you diagnose it?

Answer 13

Malassezia
Diagnosis: KOH = spagehtti and meatballs!

Yellow-green under wood’s lamp

cultures require olive oil to grow

Question 14

Treatment for dermatophyte?

Answer 14

griseofulvin
terbinafine
itraconazole
Oral for nail or hair infections but need to monitor for HEPATOTOXICITY

Question 15

TINEAS

1. capitis
2. barbae
3. axillaris
4. corporis
5. cruris
6. pedis
7. manuum
8. unhuium (onychomycosis)

Answer 15

1. scalp
2. beard
3. armpit
4. body
5. groin
6. feet
7. hand
8. Nails

Question 16

Ectothrix vs. endothrix

Answer 16

endothrix - penetrates within the hair shaft (associated with M. Canis)
-may need oral anti-fungal, topical creams don’t always penetrate the shaft

ectothrix- around the hair shaft (associated with T. tonsurans)