Diagnosis and Treatment of cutaneous fungal infections Flashcards Preview

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Flashcards in Diagnosis and Treatment of cutaneous fungal infections Deck (32):
1

What is a common superficial skin infection that may become chronic?

Tinea versicolor

2

What is tinea versicolor?

Superficial yeast infection caused by Pityrosporum ovale aka Malassezia furur

3

Where is Malassezia normally found?

What does it do on our skin?

is normally found on human skin

Organism oxidizes fatty acids in the skin and inhibits tyrosinase in the melanocytes leading to loss of pigmentation

4

Pathogenesis of tinea versicolor?

Transformation of Malassezia from yeast cells to a pathogenic mycelial form is associated with the development of clinical disease

Not related to poor hygiene

5

Risk factors for tinea versicolor?
5

What age group is it most common in?

Most common in teens (>15) and young adults

Risk factors:
1. heat,
2. humidity,
3. excessive sweating,
4. use of topical skin oils,
5. HIV infection

6

Tinea versicolor is characterized by what?

by hypopigmented lesions on the trunk that are asymptomatic

7

Clinical presentation of tinea versicolor?

(Describe the lesions?)
6

1. Asymptomatic (sometimes can be pruritic)
2. Velvety tan, pink or white macules
3. Hypopigmented areas that do not tan with the rest of the skin
4. 4-5 mm or confluent
5. Trunk, upper arms, neck and groin
6. Lesions may scale if scraped

8

Laboratory tests for tinea versicolor and what do they reveal?


Diagnosis?
3

Skin scrapings seen on KOH prep show budding spores and large hyphae “spaghetti and meatballs” (but a clinical diagnosis really)

Fungal culture not helpful

DDX:
1. vitiligo,
2. seborrheic dermatitis,
3. pityriasis alba

9

Treatment fo choice for tinea versicolor?

To prevent reocurrence?

Selenium sulfide lotion or shampoo 2.5% (Rx) once daily for 7 days

maintenance therapy twice a month

10

Treatment options for tinea versicolor?
4

Ketoconazole (shampoo)
Selenium sulfide (lotion)
Intraconazole (PO)
Fluconazole (PO)

11

How long may it take for hypopigmented areas to return to normal?

COuld take months
(80% of cases are recurrent)

12

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

Trichophyton

Microsporum

Epidermophyton

13

Dermatophytes grows where?
3

grow in the
1. skin,
2. hair and
3. nails
leading to localized symptoms

14

What do dermatophytes digest?

What does this cause? 3

Dermatophytes digest keratin

Scaling
Nails thicken and crumble
Hair loss

15

Risk factors for tinea infectious
4

1. warm, moist, occluded environments,
2. family history,
3. compromised immune system,
4. alteration in normal flora

16

How is dermatophytes spread?
3

Humans, animals, inanimate objects

17

Where are Tinea infections located and what fungal species cause it?
5

Located in the stratum corneum

Caused by dermatophytes
1. Trichophyton rubrum
2. Trichophyton tonsurans
3. Trichophyton mentagrophytes
4. Mircrosporum canis
5. Epidermophyton floccosum

18

Tinea is classified by it’s anatomic location:

Tinea corporis?

Tinea cruris?

Tinea pedis?

Tinea capitis?

Tinea unguium?

Body “ring worm”

Groin “jock itch”

Feet “athlete’s foot”

Scalp

Nails

19

Symptoms generally include what? 3

What could accompany these symptoms? 2

1. pruritus,
2. burning and
3. stinging.

If inflammatory reaction may have
1. erythema and
2. vesicles in addition to the symptoms listed above

20

Laboratory evaluation of tinea infections?
7

1. Microscopic evaluation
2. Skin margin scraping and 3. KOH prep
4. Fungal culture
5. Takes 2 weeks
6. Wood’s lamp
7. Will identify Microsporum species

21

Tinea Corpis is find where?
3

What do the lesions look like? 3

How is it transmitted? 3

How should we treat it?

Face, limbs, trunk

1. Ring shaped lesion with well-demarcated margins
2. Central clearing
3. Scaly, erythematous border

Transmitted by contact Humans, animals, sports equipment

Treat with a topical azole antifungal (apply 1-2 x daily for 2-4 weeks) continue therapy for a week after lesions clear

22

Tinea Cruris is found where? 2 spots.
Where is it not found?

Describe the lesions? 4

What is the hallmark sign?

Treatment?

Groin, inguinal folds
Spares the scrotum


1. Borders distinct
2. Lesions large,
3. erythematous
4. Macular with central clearing

Hallmark: pruritus with burning

Treatment: topical azole antifungal

23

TInea pedis is found where? 2

Descibe the lesions?

Treatment?

1. Interdigital: scaling, maceration, fissures b/w toes
2. Plantar: diffuse scaling of the soles

Acute vesicular: vesicles and bullae on the sole of the foot, great toe and instep

Treatment: topical azole antifungal (dry spray and allowing the area to be exposed to air)- also spray shoes

24

What do the lesions look like in tinea capitis?
5

1. Inflamed
2. scaly,
3. alopecic,
4. raised
patches
5. can have tender pustular nodules

25

What causes the diffuse scaling in tinea capitis?

Treatment?
2

Diffuse scaling with round alopecic patches due to broken hair shafts

Treatment: griseofulvin for 8 weeks OR terbinafine for up to 4 weeks

(CANNOT USE TOPICAL THERAPY)

26

Tinea unguium is also known as?

Where does it typically occur?

How does the infection usually occur?

Symtpoms?

Pathology?

Also known as onychomycosis

Typically toenails but can affect fingernails as well

Infection usually moves distal to proximal

Usually asymptomatic

Fungus is causing cells to lyse and build up

27

Treatment for tinea unguium:
Fingernail?
Toe Nails?

What should we monitor? 2

What is the alternative?

1. Treat with oral terbinafine (Lamisal) 250 mg po qday X 6 weeks (fingernails); 12 weeks for toenails.

2. Monitor LFTs, CBC

3. Alternative is itraconazole (Sporanox)

28

What is a candidiasis found in the axillae, under breasts, groin, and intergluteal folds?

What is a candidiasis found on the glans penis?

What is a candidiasis found that produces follicular pustules?

What is a candidiasis found in nail folds?

What is a candidiasis found in the mouth and tongue?

What is a candidiasis found in babies?

Intertrigo


Balantitis

Candidal folliculitis


Candidal paronychia

Thrush

Diaper dermatitis

29

Risk factors for candidiasis
7

1. Infection
2. Recent antibiotic therapy
3. Diabetes
4. Systemic and topical steroids
5. Immunosuppression
6. Warm, moist conditions
7. Break in the skin

30

Treatment of candidiasis: Thrush? 2

Nystatin
Clotrimazole

31

Tretament of cutaneous candidiasis:
3

If failure of topical therapy?

1. Powder for macerated areas (Nystatin)
2. Topical clotrimazole (Lotrimin),
3. ketoconazole

If failure of topical therapy
-Oral fluconazole (Diflucan)

32

What are the topical azoles?
3

Azoles:
1. Miconazole;
2. Clotrimazole;
3. Ketoconazole