Dx.. and Tx. of Cutaneous Fungal Infections

Question 1

Tinea versicolor (Pityriasis versicolor)

Answer 1

Superficial yeast infection caused by Pityrosporum ovale aka Malassezia furur
(Organism oxidizes fatty acids in the skin and inhibits tyrosinase in the melanocytes leading to loss of pigmentation)

Question 2

Laboratory findings of tinea versicolor

Answer 2

Skin scrapings seen on KOH prep show budding spores and large hyphae “spaghetti and meatballs”
Fungal culture not helpful

Question 3

Tinea versicolor Treatment

Answer 3

Selenium sulfide lotion or shampoo 2.5% (Rx)

Question 4

3 species of fungi that cause human infection (dermatophytes).

Answer 4

Trichophyton
Microsporum
Epidermophyton

Question 5

Tinea is classified by it’s anatomic location.

Answer 5

Tinea corporis- Body “ring worm”
Tinea cruris- Groin “jock itch”
Tinea pedis- Feet “athlete’s foot”
Tinea capitis- Scalp
Tinea unguium- Nails

Question 6

Tinea Corporis, Pedis, Cruris Treatment

Answer 6

Treat with a topical azole antifungal (apply 1-2 x daily for 2-4 weeks) continue therapy for a week after lesions clear
(Trebeniphim-Lamicil, Mechonazole- Monistat, Chlotrenizol- )

Question 7

Tinea capitis Treatment

Answer 7

griseofulvin for 8 weeks OR terbinafine for up to 4 weeks

Question 8

Tinea unguium Treatment

Answer 8

oral itraconazole x 12 weeks or terbinafine if itraconazole fails

Question 9

Cutaneous candidiasis

Answer 9

Intertrigo- Axillae, under breasts, groin, intergluteal folds
Balantitis- Glans penis
Candidal folliculitis- Follicular pustules
Candidal paronychia- Nail folds
Thrush- Mouth and tongue
Diaper dermatitis

Question 10

Treatment of candidiasis

Answer 10

Thrush:
Nystatin
Clotrimazole

Cutaneous:
Powder for macerated areas (Nystatin)
Topical clotrimazole (Lotrimin), ketoconazole

If failure of topical therapy:
Oral fluconazole (Diflucan)