Fungal Skin Infections - PR Flashcards
What are tests available to identify cutaneous fungal infections?
- KOH prep
- Culture
- Examination by woods lamp
What would be advantages to obtaining a fungal culture?
-Helps identify the source of the infection (i.e. Tinea corporis may be caused by different fungal species with different environmental sources)
What is an infection that is NOT caused by a fungus, but fluoresces with a Wood’s lamp?
Erythrasma caused by Corynebacterium minutissimum
What are the two types of Fungal skin infections?
1) Dermatophytes
2) Yeast (candida)
What are some characteristics of Tinea pedis?
- 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
What is the Tx for Tinea pedis?
- 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)
What is the typical presentation of a Tinea Corporis Lesion?
Annular lesion with central clearing → often itchy
What are Tx options for Tinea Corporis?
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)
What is the most common dermatological disorder in school-aged children in the US?
Tinea capitis (Trichophyton tonsurans most common)
What is the clinical presentation of Tinea Capitis?
- 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
What is the Tx for Tinea capitis?
- Topical agents ineffective
- DOC → Terbinafine (may require up to 4 weeks of Tx)
Untreated tinea capitis has a significant percentage of progressing into a…?
Kerion: painful, inflammatory boggy mass with broken hair follicles
True or False: Tinea versicolor is caused by a dermatophyte?
False, T. versicolor is caused by a species of Malassezia (a lipophilic yeast that is a normal resident of keratin in the skin)
What is the clinical presentation of Tinea versicolor?
- 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)
What are treatment options for Tinea Versicolor?
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
True or False: Seborrheic Dermatitis is an inflammatory reaction and is a chronic condition that can be controlled but not cured?
True
What are the typical findings on a patient with Seborrheic Dermatitis?
- Fine white scale to erythematous patches and plaques with greasy, yellowish scale
- May also cause areas of hypopigmentation
What are Tx options for patients with Seborrheic Dermatitis?
- Shampoos
- Imidazole creams
- Low-potency topical steroids (safe to use for flares on the face)
What are the most common manifestations of candidiasis in men/women/children?
- Men: balanitis
- Women: vaginitis
- Children: oral thrush
What is the Tx for vaginal candidiasis infection?
- Miconazole Nitrate (Monistat) administered intravaginally
- Fluconazole (Diflucan) 150 mg administered orally
What are characteristics of Thrush?
- raised white patches inside the oral cavity on mucosa and tongue
- If scraped → reveals raw, erythematous, bleeding base
Chronic atrophic stomatitis is common in what patients?
Patients with diabetes and patients who wear dentures
What are treatment options for Thrush in children and adults?
- Children: Nystatin oral suspension
- Adults: Fluconazole 200 mg/day is first-line treatment option
What differentiates candidal diaper dermatitis from other eruptions?
Satellite papules and pustules
Suspect diaper candidiasis when rash does not improve with application of barrier creams
What is the treatment of choice for diaper candidiasis?
Nystatin cream or ointment
if inflammation present → add hydrocortisone 1% cream for limited time
What is the classical symptom/sign of candida intertrigo?
- Burns more than itches
- Satellite macules, papules, or pustules, around the erythema in the fold
True or False: Allylamines (Terbinafine, naftifene) are effective for Candida yeast?
False, NOT effective
