CHAPTER 15: FUNGI AND YEASTS (SUPERFICIAL)

Question 1

MOA of imidazoles

Answer 1

inhibition of cytochrome P450 14α-demethylase, an sential enzyme in ergosterol synthesis.

Question 2

MOA of Nystatin

Answer 2

a polyene that works by irreversibly binding to ergosterol, an essential component of fungal cell membranes.

Question 3

Naftifine, terbinafine, and butenafine are allylamines, and their mode of action is

Answer 3

inhibition of squalene epoxydation.

Question 4

Black dot ringworm, seborrheic like scaling and inflammatory kerion

This organism in tinea capitis produces spores WITHIN the hair shaft

Do not produce fluorescence in Wood’s lamp

Answer 4

Trichophyton tonsurans

Question 5

Organism in tinea capitis that produce spores OUTSIDE the hair shaft

Fluoresce under Wood’s lamp
Scaly, erythematous papules with loose and broken off hairs

Answer 5

Microsporum canis

Question 6

Deep tender boggy plaques exuding pus in tinea capitis

Scarring, permanent alopecia

Answer 6

Kerion celsii

Question 7

Appears chiefly on scalp but may affect glabrous skin and nails

Scalp- concave yellow sulfur crusts around loose wiry hairs

Atrophic scarring- glossy smooth white patch
Glabrous skin- cup shaped crusts with mousy odor

Answer 7

Favus

Question 8

Cup shaped crusts usually pierced by a hair on skin with a distinctive mousy odor in tinea infection

Answer 8

Scutulae

Question 9

Infected tinea hairs will fluoresce what color in Wood’s light?

Answer 9

Bright green or yellow green

Trichophyton- does not fluoresce

Question 10

Treatment for tinea capitis in children

Answer 10

Griseofulvin 10mg/kg/day

2-4 months

Question 11

Treatment for trichophyton infections in tinea

Answer 11

Terbinafine 3-6mg/kg/day x 1-4 weeks

Adjunct: selenium sulfide shampoo or ketoconazole shampoo 5 mins 3x a week

Question 12

vesicular, lichenoid, papulosquamous, or pustular and representing a systemic reaction to fungal antigens.

inflammatory tinea capitis

Answer 12

Id reaction

Question 13

Tinea barbae is different from staphylococcal folliculitis (sycosis vulgaris) by

Answer 13

Sparing of upper lip

Unilateral involvement

Question 14

Q
Circular, sharply circumscribed, slightly erythematous, dry, scaly hypopigmented patches
Progressive central clearing

Found in the body except in face, beard, hands, feet and groin

Answer 14

Tinea corporis

Question 15

Tx for Tinea corporis

Answer 15

Topical: miconazole , clotrimazole BID x 2-4 wks

Ketoconazole, terbinafine OD
Terbinafine -1 wk

Systemic
Trichophyton: giseofulvin, tebinafine, fluconazole

Question 16

Deep pustular tinea circinata resembling a carbuncle or kerion on glabrous skin

Follicles distended with purulent ma

Answer 16

Fungal folliculitis

Majocchi granuloma

Question 17

Tinea incognito is an atypical lesion that are widespread and may lack an advancing scaly border

It is usually caused by

Answer 17

Treatment with topical corticosteroid or calcineurin inhibitors

Question 18

Infection of the nail plate by a fungus is called

Answer 18

Onychomycosis

Tinea unguium

Question 19

Onychomycosis caused by what organism?

Starts at distal corner of the nail and involves the junction of the nail and bed

Yellow discoloration, spreads proximally
Nail becomes brittle

Answer 19

T. rubrum

Question 20

A superficial fungal infection

concentrically
arranged rings or parallel, undulating lines of scales overlapping each other like shingles on a roof (imbrex means “shingle”)

causative fungus is Trichophyton concentricum,

Answer 20

Tinea imbricata (Tokelau)

Question 21

also known as jock itch and crotch itch

dx: KOH exam, fungal culture, biopsy , immunoflurescence

Answer 21

Tinea cruris

Question 22

what type of onchomycosis is an indication of an HIV infection?

Answer 22

proximal subungual onchomycosis

caused by T. rubrum and Trichophyton meninii

Question 23

type of onchomycosis where there is an invasion of the toenail plate on the SURFACE of the nail?

Answer 23

white superficial onchomycosis ( leukonychia trichophytica)

Question 24

management of onychomycosis

Answer 24

topical: ciclopirox, eficonazole, and amorolfine nail lacquers.

adult with fingernail involvement:
1. terbinafine is given in doses of 250 mg/day for 6–8 weeks. for toenails, 12-16 wks
2. Itraconazole given as pulsed dosing, 200 mg twice daily for 1 week of each month, for 2 months when treating fingernails and for 3–4 months when treating toenails.
3. Fluconazole, 150–300 mg once weekly for 6–12 months, appears to be effective.

Question 25

Side effect that should be noted when using itraconazole and terbinafine, ketoconazole

Answer 25

liver function abnormalities (alanine transami- nase [ALT], aspartate transaminase [AST], alkaline phospha- tase, total bilirubin). or development of signs or symptoms suggestive of liver dysfunction.

Question 26

Grayish white membranous plaques found on the surface of the mucous membrane Base is moist reddish and macerated Often first manifestation of AIDS

Answer 26

oral candidiasis (thrush)

Question 27

Treatment for oral thrush

Answer 27

infants: oral nystatin suspension adults: clotrimazole, fluconazole immunocompromised: itraconazole, terbinafine

Question 28

Maceration and transverse fissuring of the oral commissures Bilateral involvement

Answer 28

perleche or angular cheilitis

Question 29

Pruritic intertriginous eruptions between folds Pink to red moist patches surrounded by a colarette scale

Answer 29

Candidal intertrigo

Question 30

Candidal intertrigo treatment

Answer 30

topical anticandidal- recurrence is common topical anticandidal + corticosteroid castellani paint

Question 31

Treatment for diaper candidiasis

Answer 31

zinc oxide ointment oral nystatin

Question 32

Infection with Candida limited to mucosal surfaces, skin and nails Onset before 6 years old Hyperkeratotic, horn like or granulomatous lesions

Answer 32

chronic mucocutaneous candidiasis

Question 33

Gold standard for systemic candidiasis treatment

Answer 33

Amphotericin B | safer option is liposomal amphotericin

Question 34

Dark pinhead to pebble sized formations on the hairs of scalp, brows, lashes or beard Distributed irregularly on the hair shaft

Answer 34

black piedra

Question 35

Yellow or beige colored soft slimy sheath coating the hair shaft caused by trichosporon

Answer 35

white piedra

Question 36

Treatment for piedra

Answer 36

1. cutting or shaving the hair 2. black piedra: Oral and topical terbinafine 3. for white piedra: oral itraconazole, topical imidazoles, ciclopirox olamine, 2% sele- nium sulfide, 6% precipitated sulfur in petrolatum, chlorhexi- dine solutions, Castellani paint, zinc pyrithione, amphotericin B lotion, and 2–10% glutaraldehyde

Question 37

Hypo or hyperpigmented coalescing scaly macules on the trunk and upper arms Favors oily areas of the skin, occurs during summer Mild itching and inflammation around patches

Answer 37

tinea versicolor

Question 38

Treatment for tinea versicolor

Answer 38

1. Imidazoles, triazoles, selenium sulfide, ciclopirox olamine, zinc pyrithione, sulfur preparations, salicylic acid prepara- tions, propylene glycol, and benzoyl peroxide have been used successfully as topical agents. 2. adults: Oral itraconazole, 200 mg once daily for 7 days; Fluconazole, 400 mg once daily