Fungal Skin Infections - PR

Question 1

What are tests available to identify cutaneous fungal infections?

Answer 1

• KOH prep
• Culture
• Examination by woods lamp

Question 2

What would be advantages to obtaining a fungal culture?

Answer 2

-Helps identify the source of the infection (i.e. Tinea corporis may be caused by different fungal species with different environmental sources)

Question 3

What is an infection that is NOT caused by a fungus, but fluoresces with a Wood’s lamp?

Answer 3

Erythrasma caused by Corynebacterium minutissimum

Question 4

What are the two types of Fungal skin infections?

Answer 4

1) Dermatophytes

2) Yeast (candida)

Question 5

What are some characteristics of Tinea pedis?

Answer 5

• Most commonly caused by Trichophyton rubrum
• Almost inevitable in immunocompromised patients
• 3 clinical patterns of infection
  1) Interdigital (MC)
  2) Moccasin (1 hand, 2 feet)
  3) Vesiculobullous

Question 6

What is the Tx for Tinea pedis?

Answer 6

• Hygiene & topical antifungals
• Imidazoles (Clotrimazole OTC) → First Line
• Ciclopirox (Loprox) → Second line
• Systemic Antifungals for severe or refractory cases (Terbinafine 250 mg PO q.d. x 14 days)

Question 7

What is the typical presentation of a Tinea Corporis Lesion?

Answer 7

Annular lesion with central clearing → often itchy

Question 8

What are Tx options for Tinea Corporis?

Answer 8

1) Topical antifungals
- applied for 2+ weeks after resolution
- Imidazoles
2) Oral antifungals
- If there is a poor response to topicals
- Terbinafine q.d. x 2 weeks (check liver function test w/ extended use)

Question 9

What is the most common dermatological disorder in school-aged children in the US?

Answer 9

Tinea capitis (Trichophyton tonsurans most common)

Question 10

What is the clinical presentation of Tinea Capitis?

Answer 10

• May be :
  1) non-inflammatory (black dot, seborrheic)
  2) inflammatory (kerion)
  3) combination of both
• Broken hairs are prominent feature
• Often presents with postauricular, posterior cervical, or occipital lymphadenopathy

Question 11

What is the Tx for Tinea capitis?

Answer 11

• Topical agents ineffective

- DOC → Terbinafine (may require up to 4 weeks of Tx)

Question 12

Untreated tinea capitis has a significant percentage of progressing into a…?

Answer 12

Kerion: painful, inflammatory boggy mass with broken hair follicles

Question 13

True or False: Tinea versicolor is caused by a dermatophyte?

Answer 13

False, T. versicolor is caused by a species of Malassezia (a lipophilic yeast that is a normal resident of keratin in the skin)

Question 14

What is the clinical presentation of Tinea versicolor?

Answer 14

• Well-demarcated, tan, salmon, or hypopigmented or hyperpigmented patches - most commonly on the trunk and arms
• Visible scale often not present, but becomes apparent when rubbed with finger or scalpel blade (Dx feature of T. versicolor)

Question 15

What are treatment options for Tinea Versicolor?

Answer 15

1) First-line: Topicals
- Shampoos (selenium sulfide 2%)
- Ketoconazole shampoo
- Imidazole creams (ketoconazole or clotrimazole)
2) Oral Medication:
- Used when topical therapy fails
- Fluconazole 300 mg / week for 2-4 weeks
- Itraconazole 200 mg / day x 7 days

Question 16

True or False: Seborrheic Dermatitis is an inflammatory reaction and is a chronic condition that can be controlled but not cured?

Answer 16

True

Question 17

What are the typical findings on a patient with Seborrheic Dermatitis?

Answer 17

• Fine white scale to erythematous patches and plaques with greasy, yellowish scale
• May also cause areas of hypopigmentation

Question 18

What are Tx options for patients with Seborrheic Dermatitis?

Answer 18

• Shampoos
• Imidazole creams
• Low-potency topical steroids (safe to use for flares on the face)

Question 19

What are the most common manifestations of candidiasis in men/women/children?

Answer 19

• Men: balanitis
• Women: vaginitis
• Children: oral thrush

Question 20

What is the Tx for vaginal candidiasis infection?

Answer 20

• Miconazole Nitrate (Monistat) administered intravaginally

- Fluconazole (Diflucan) 150 mg administered orally

Question 21

What are characteristics of Thrush?

Answer 21

• raised white patches inside the oral cavity on mucosa and tongue
• If scraped → reveals raw, erythematous, bleeding base

Question 22

Chronic atrophic stomatitis is common in what patients?

Answer 22

Patients with diabetes and patients who wear dentures

Question 23

What are treatment options for Thrush in children and adults?

Answer 23

• Children: Nystatin oral suspension

- Adults: Fluconazole 200 mg/day is first-line treatment option

Question 24

What differentiates candidal diaper dermatitis from other eruptions?

Answer 24

Satellite papules and pustules

Suspect diaper candidiasis when rash does not improve with application of barrier creams

Question 25

What is the treatment of choice for diaper candidiasis?

Answer 25

Nystatin cream or ointment

if inflammation present → add hydrocortisone 1% cream for limited time

Question 26

What is the classical symptom/sign of candida intertrigo?

Answer 26

• Burns more than itches

- Satellite macules, papules, or pustules, around the erythema in the fold

Question 27

True or False: Allylamines (Terbinafine, naftifene) are effective for Candida yeast?

Answer 27

False, NOT effective