Derm - Dermatophyte Infections - Exam 1 Flashcards
How is Tinea Capitis acquired?
Via direct contact with an infected individual or animal
Via contaminated object (comb, brush, tiara, wig, hat)
What are the ways in which Tinea Capitis can present clinically?
- Scaly patches with alopecia
- Patches of alopecia with black dots
- Widespread scaling with subtle hair loss
- Kerion
- Favus
What is a kerion?
A boggy edematous painful plaque
What are some associated signs of Tinea Capitis?
- Cervical adenopathy
- Dermatophytid reaction
- Erythema Nodosum
What is the most effective treatment for Tinea Capitis?
Topical Griseofulvin
How does Tinea Corporis present as clinically?
- Pruritic, annular, erythematous plaque
- Central clearing
- Raised, advancing border
What is the most effective treatment for Tinea Corporis?
Clotrimazole (topical antifungal) for at least 2 weeks
What is the treatment choice in special circumstances/resistant cases of Tinea Corporis?
Oral itraconazole
What are some factors that contribute to the development of Tinea Cruris?
- Male
- Sweaty/humid
- Obesity/skin folds
- Occlusive clothing
- Athlete’s foot
How does Tinea Cruris present as clinically?
- Well-marginated, scaly, annular plaque with raised border
- Extends from the inguinal fold to the inner thigh
- Scrotum typically spared
What is the most effective treatment for Tinea Cruris?
- Clotrimazole (topical antifungal)
- Treat associated Tinea pedis and/or onychomycosis
- Daily drying powder
- Lifestyle considerations such as avoiding tight clothing and weight loss
What is the most effective medication for resistant cases of Tinea Cruris?
Oral itraconazole
What is the most common dermatophytosis in the world?
Tinea Pedis
What are risk factors of Tinea Pedis?
- Occlusive footwear
- Communal baths/showers/pools
How does acute Tinea Pedis present as clinically?
- Itchy/painful vesicles or bulla following sweating
- Secondary staph infections are common
How does chronic Tinea Pedis commonly present as clinically?
- Erosions/scales between toes (especially 3rd and 4th)
- Interdigital fissures
It is known that chronic Tinea pedis can present clinically as scales and fissures between toes, but how else can it present?
- “Moccasin Ringworm”
- Sharp demarcation with accumulated scale in the skin creases
- May present with tinea manuum (two feet, one hand)
What is the most effective treatment for Tinea pedis?
- Clotrimazole (topical antifungal)
- Burow’s wet dressings for vesiculation or maceration, 20 minutes BID-TID
- Treat secondary infections
- Lifestyle considerations (foot powder, treatment of shoes, proper footwear)
What is the most effective medication treatment for chronic/extensive Tinea pedis?
Oral itraconazole
What are risk factors for Onychomycosis?
- Advanced age
- Tinea pedis
- Genetics
- Immunodeficiency
- Household infection
What are the three common ways in which Onychomycosis can present?
- Distal subungual onychomycosis
- Proximal subungual onychomycosis
- White superficial onychomycosis
What is the most common presentation of Onychomycosis?
Distal subungual onychomycosis
What are the common characteristics of Distal subungual onychomycosis?
- Typically starts with great toe
- White/brown/yellow discoloration starts at distal corner and spreads towards the cuticle
- Distal end of the nail breaks, exposing the nail bed
What are the common characteristics of Proximal subungual onychomycosis?
- Starts near cuticle and progresses distally
- Usually seen in severely immunocompromised population (AIDS)
What are the common characteristics of White superficial onychomycosis?
- Starts with dull white spots on surface of the nail plate
- Spreads centrifugally until entire nail is involved
- Lesions can be scraped for lab sample
What is a common pathogen of fingernail onychomycosis?
Yeast usually due to Candida Albicans
What can fingernail onychomycosis cause?
- Thickening of nail with yellow/brown discoloration
- Chronic paronychia
How is the diagnosis of Onychomycosis confirmed?
- KOH prep of nail scrapings
- Culture
- Histopathology (biopsy)
When should treatment for Onychomycosis be considered?
- Has a history of cellulitis
- Diabetic
- Desires cosmetic improvement
- Complains of discomfort/pain
What is the most effective treatment for Nondermatophyte onychomyosis?
Oral itraconazole
- 6 weeks for fingernails
- 12 weeks for toenails
What is the most effective treatment for Dermatophyte onychomyosis?
Oral terbinafine
- 6 weeks for fingernails
- 12 weeks for toenails
What is Intertrigo?
Any infectious or noninfectious inflammatory condition of two closely opposed skin surfaces
What are risk factors for Intertrigo?
- Moisture
- Skin friction
- Immunocompromised
What does Candidal Intertrigo typically affect?
The groin, mammary/abdominal folds, web spaces, and axilla
What are the common characteristics of Candidal Intertrigo?
- Erythematous, macerated plaques and erosions
- Satellite papules/pustules
- Fine peripheral scaling
What is typically the most effective treatment for Candidal Intertrigo?
Topical Nystatin x 2-4 weeks
What is typically the most effective treatment for resistant/severe cases of Candidal Intertrigo?
Oral Fluconazole x 2-6 weeks
What are preventative measures for Candidal Intertrigo?
- Drying agents
- Weight loss
- Address underlying medical conditions
What is Tinea Versicolor?
Fungal infection of the skin
Tinea Versicolor is most common in which populations?
- Tropical climate
- Adolescents/young adults
What are risk factors for Tinea Versicolor?
- Hyperhidrosis
- Genetics
- Immunosuppresion
What are some common characteristics of Tinea Versicolor?
- Macules, patches, plaques on trunk/UE
- Can coalesce
- Often have fine scale
- Typically asymptomatic but can be mildly pruritic
How is Tinea Versicolor diagnosed?
- Physical exam
- KOH prep
- Wood’s lamp (yellow to yellow-green fluorescene in 1/3)
How is Tinea Versicolor typically treated?
- Clotrimazole, a topical antifungal
- Selenium sulfide (lotion, shampoo, foam)
- Zinc Pyrithione shampoos
When is systemic treatment used in Tinea Versicolor? What medication is the most effective?
- Reserved for extensive disease or failed topical therapy
- Oral itraconazole x 5-7 days
- Not used in children
What does Scabies classically present with?
- Initial lesion
- Burrow is pathognomonic
- Head and back are often spared
- Severe pruritus which is worse at night
How can Scabies be diagnosed?
- Visualization of burrow
- Microscopic identification of the mite, eggs, or fecal pellets
- Dermatoscope
How can Scabies be treated?
- Permethrin 5% cream - initial treatment + 2nd application 10-14 days later
- Oral Ivermectin - single dose repeated two weeks later
What population is most commonly affected by pubic lice?
Teens and young adults
How are pubic lice transmitted?
Primarily via sexual contact
How does pubic lice present?
Itching in the groin/axilla
What is the treatment for pubic lice?
- Permethrin 1% cream - initial treatment + 2nd application 10 days later
Onychomycosis increases the risk of other infections, especially in which other population?
The immunocompromised population
What does the term Versicolor refer to?
The variety of colors that the infection may present with (hypopigmented, hyperpigmented, erythematous)
How can Tinea Capitis be diagnosed?
- Physical exam
- Wood’s lamp
- KOH prep
- Dermascope
- Culture
How is Tinea Pedis diagnosed?
- History and physical exam
- KOH prep
- Culture
- Gram stain if bacterial infection suspected
Describe Favus and what condition is it related to?
Multiple cup-shaped yellow crusts
Seen in tinea capitus
What happens in Norwegian scabies?
The lesions become crusted over and fissures provide an avenue for bacteria which can lead to sepsis.
Oral medications are required.
