Fungal Skin Infections (PHARM)

Question 1

Superficial fungal infections

Answer 1

-Dermatophytes “ringworm” (Dermatophytes are specialized in obtaining nutrients from keratinized tissues, such as the skin, hair, and nails)

-Candida “yeast”

-Tinea versicolor (pityriasis versicolor, malassezia furfur, sub dermatitis on your scalp)

Question 2

Pathophysiology of fungal infection

Answer 2

-Produces an enzyme that digest keratin causing epidermal scale
-Only penetrate the stratum corneum
-Fungal cell wall ergosterol instead of cholesterol

Question 3

Dermatophytes examples

Answer 3

-Tinea corporis (smooth body)
-Tinea cruis (groin)
-Tinea pedis (feet)
-Tinea manuum (hands)
-Tinea barbar (beard)
-Onychomycosis (nail)

Question 4

Dermatophytid Reaction (ID) reaction

Answer 4

-Sterile eruption of vesicles on sides of fingers (palms and soles) following a dermatophyte infection occurring to a fungal infection elsewhere

-Management: Burrow’s soaks and corticosteroids

Question 5

Topical anti-fungals (broader spectrums)

Answer 5

-Imidazoles are effective: clotrimazole 1%, micondazole 2%, ketocondazole 1% apply bID for 4 weeks

Question 6

Topical anti-fungals (athlete’s foot)

Answer 6

-Lamisil (terbinafine) once daily for one week
-not effective for yeast or candidas

Question 7

Topical solutions for Nail Fungus

Answer 7

-Ciclopirox 8% nai
-Efinaconazole 10%
-apply 48 weeks

Question 8

Drug of choice for onchomycosis

Answer 8

-Terbinafine orally, do LFT before and within 4 weeks

Question 9

Terbinafine MOA

Answer 9

-Inhibits squalene epoxidase enzyme responsible for fungal biosynthesis leading to deficiency in ergosterol resulting in cell death.

-12 to 24 weeks of treatment
-LFT prior and 4 wks

Question 10

Itraconazole systemic anti fungal

Answer 10

-highly affinity for keratin
-pulse dosing due to long half life (so not preferable over terbinafine)
-LFT prior and 4 wks
-not as effective as terbinafine

Question 11

Cutaneous candidiasis areas:

Answer 11

-Intertrigo (skin folds)
-paronychia (nail fods)
-cheilitis (Lips)
-balanitis (Foreskin head of penis)

-nystatin cream or azole cream for 2-3 weeks
-Tolnaftate (tin actin) or terbinafine is not effective

Question 12

Tinea versicolor (pityriasis versicolor)

Answer 12

-Not a true dermatophyte
-Yeast like fungi
-Overgrowth of normal Malassezia
-occurs more in hot conditions
-generally in trunk, upper shoulders and arms
-scaly macula’s with fine scale hyper pigmented on regular skin or hypo pigmented when ski is tanned

Question 13

Treatment of Tinea versicolor

Answer 13

-Topical antifungals (not nystatin)
-Selenium sulfide 2.5% shampoo once for 7-14 days wash 5-10 mins after
-ketoconazole 2% cream once daily for 14 days
-ketoconazole 2% shampoo 3 days daily wash off after 5 min