Fungal Infections Flashcards
(28 cards)
Likes moist, occluded skin
Host factors: IC, Diabetes, Obesity, Hyperhydrosis, Steroid therapy
Typically presents as thick, white curdy material
Candidiasis
What is the causative agent in Candidiasis?
Candida albicans
Chronic asymptomatic scaling epidermomycosis
Characterized by well-demarcated scaling patches with variable
pigmentation occurring most commonly on the trunk
In areas of sun-induced pigmentation 🡪 commonly presents after UV exposure
Age of onset – young adults (can affect all ages)
Duration can be months to years
Typically asymptomatic - May have mild pruritis
Pityriasis/Tinea Versicolor
This condition is also called Tinea Versicolor
Pityriasis
What is the causative organism for Pityriasis/Tinea Versicolor?
Malassezia globose (yeast-like fungus)
What are some predisposing factors for the development of Pityriasis/Tinea Versicolor?
High temperatures/relative humidity (warm, moist environments)
Oily skin
Hyperhidrosis
Hereditary factors
Glucocorticoid treatment
Immunodeficiency
Lipid application (i.e. Cocoa butter)
Well-demarcated scaling patches usually on trunk with variable pigmentation
Ring-like pattern, or circular
Dribble-down pattern
Vary in size
Discoloration:
Untanned skin- lesions are light brown
Tanned skin - lesions are white
Dark skin - lesions are dark brown
Mild pruritis
Pityriasis Versicolor
What are the diagnostic tests to diagnose Pityriasis Versicolor?
KOH prep will show “spaghetti and meatballs” - Large blunt hyphae and thick walled budding spores
Wood’s lamp - Blue-green fluorescence
What are some treatment options for Pityriasis Versicolor?
Selenium sulfide
2.5% ketoconazole shampoo
Oral Ketoconazole
Terbinafine (Lamisil) 1% solution
“azole” creams
Oral only if severe
Dermatophyte infections of the trunk, legs, arms, and/or neck (excludes feet, hands, and groin)
Affects all ages
Transmission - Autoinoculation from other parts of the body, contact with animals or contaminated soil
Occupational risk – animal workers
Incubation period: days to months
Typically asymptomatic - May have mild pruritis
Tinea Corporis
What is the causative agent of Tinea Corporis?
T. rubrum (most common)
Single and occasionally scattered lesions
Small to large scaling, sharply marginated plaques with or without pustules or vesicles (usually at margins)
Peripheral enlargement and central clearing produces annular
configuration with concentric rings or arcuate lesions (forms arches)
Tinea Corporis
List some other conditions to consider in your differential diagnoses when evaluating for tinea corporis
Psoriasis
Lupus erythematous
Syphilis
Granuloma annulare
Pityriasis rosea
What are the treatment options for Tinea Corporis?
Azole creams
Griseofulvin (if need systemic therapy)
Dermatophytic infection of the foot
Can spread to other sites
Age of onset: Late childhood or young adults (Ages 20-50 years most common)
More common in males than women
Transmission - Walking barefoot on contaminated floors
Arthrospores can survive in human scales for 12 months
Tinea Pedis
What are some predisposing factors for tinea pedis?
Hot, humid weather
Occlusive footwear
Excessive sweating
What are the four types of tinea pedis?
Interdigital type
Moccasin type
Inflammatory/Bullous type
Ulcerative Type
What are some preventative measure for tinea pedis?
Wear shower shoes
Wash with benzoyl peroxide bar
Allow feet to dry before putting on
socks and shoes
What is the treatment for tinea pedis?
“azoles” - apply to affected sites BID for 2-4 weeks
What type of tinea pedis is described below?
Two patterns: Dry, scaling; Maceration
Peeling and fissuring between the toe webs
Hyperhidrosis common
Most common site: between 4th and 5th toes
Can spread to adjacent areas of the feet
Treatment -
Acute: Burows solution
Chronic: aluminum chloride hexahydrate 20% (BID)
Interdigital Type
What type of tinea pedis is described below?
Well-demarcated erythema with minute papules on margin, fine
white scaling, and hyperkeratosis
Confined to heels, soles, lateral borders of the feet
Involving area covered by a “ballet slipper”
Bilateral involvement common
Most difficult to treat
Moccasin Type
Which type of tinea pedis is hardest to treat?
Moccasin Type
What type of tinea pedis is described below?
Vesicles or bullae filled with clear fluid
Pus usually indicates secondary S. aureus infection or group A streptococcus
Treatment:
Acute: use cool compresses
Severe: systemic glucocorticoids are indicated
Inflammatory/Bullous Type
What type of tinea pedis is described below?
Extension of interdigital tinea pedis onto dorsal and plantar foot
Usually complicated by bacterial infection
Ulcerative Type
