Cutaneous Mycoses Flashcards
Which Sketchy image represents Malassezia furfur?
Which Sketchy image represents Epidermophyton spp., Trichophyton spp., and Microsporum spp. (dermatophytes)?
Which Sketchy image represents Sporothrix schenckii?
Identify as many of the marked points in this image as you can.
Note: this image represents Malassezia furfur**.
Identify as many of the marked points in this image as you can.
Note: this image represents Epidermophyton spp., Trichophyton spp., and Microsporum spp. (dermatophytes).
Identify as many of the marked points in this image as you can.
Note: this image represents Sporothrix schenckii**.
Malassezia furfur is a fungus that causes what kind of mycoses?
Cutaneous
(pityriasis (tinea) versicolor)
What infectious agent causes pityriasis (tinea) versicolor?
Malassezia furfur
Describe the various presentations of infection with pytiriaisis (tinea) versicolor.
A superficial skin infection characterized by hypopigmented, hyperpigmented, or erythematous macules on the trunk and upper extremities
(can cause inability to tan in affected areas)
Malassezia furfur is classically described as having a “_____________” appearance on KOH mount of skin scrapings.
Malassezia furfur is classically described as having a “spaghetti and meatballs” appearance on KOH mount of skin scrapings.
______________ is classically described as having a “spaghetti and meatballs” appearance on KOH mount of skin scrapings.
Malassezia furfur is classically described as having a “spaghetti and meatballs” appearance on KOH mount of skin scrapings.
Which form of Malassezia furfur is pathogenic, yeast or mycelial (mold)?
Mycelial (mold)
The conversion of Malassezia furfur yeast cells to the pathogenic mycelial form is associated with what?
Heat and humidity
Malassezia furfur is a _______-dependent fungus (the ______ body may be the predominant location of infection due to greater sebum production in this location).
Malassezia furfur is a lipid-dependent fungus (the upper body may be the predominant location of infection due to greater sebum production in this location).
Malassezia furfur generally stays confined to what skin layer(s)?
The stratum corneum
Malassezia furfur fungemia is associated with neonates in what situation(s)?
Receiving total parenteral nutrition (TPN) through catheters
How is infection with Malassezia fufur infection treated?
Topical selenium sulfide (Selsun Blue)
Name three dermatophytes.
What disease do they cause?
Epidermophyton spp., Trichophyton spp., Microsporum spp.
Tinea
What fungal category causes ringworm?
Dermatophytes
Are dermatophytes part of the normal skin flora?
No
Tinea capitus is found on what part of the body?
And tinea cruris?
And tinea pedis (what is another name for this lesion)?
And tinea corporis?
The head and scalp;
the groin;
the foot (athlete’s foot)
the body
Epidermophyton spp., Trichophyton spp., and Microsporum spp. (dermatophytes) can be acquired via contact with what?
Infected animals
True/False.
Cutaneous lesions caused by dermatophytes (i.e. tinea / ringworm) are often pruritic.
True.
The hyphae of Epidermophyton spp., Trichophyton spp., and Microsporum spp. (dermatophytes) can be seen with _____ mount of skin scrapings.
The hyphae of Epidermophyton spp., Trichophyton spp., and Microsporum spp. (dermatophytes) can be seen with KOH mount of skin scrapings.
A Wood’s lamp can be used to detect the presence of dermatophytes of the _____________ genus.
A Wood’s lamp can be used to detect the presence of dermatophytes of the Microsporum genus.
A _____________ can be used to detect the presence of dermatophytes of the Microsporum genus.
A Wood’s lamp can be used to detect the presence of dermatophytes of the Microsporum genus.
What is the mainstay of treatment for cutaneous dermatophyte infection (tinea caused by Epidermophyton spp., Trichophyton spp., or Microsporum spp.)?
Topical azoles
True/False.
Dermatophytes cause tinea (ringworm) but do not cause fungal infections of the nail.
False.
Dermatophytes cause tinea (ringworm) and also can cause fungal infections of the nail (onychomycosis).
Name two effective treatments for dermatophyte onychomycosis.
Terbinafine;
griseofulvin
Sporothrix schenckii is a _________ fungus that causes _________ mycosis.
Sporothrix schenckii is a dimorphic fungus that causes cutaneous mycosis.
Where is Sporothrix schenckii naturally found?
Soil and on plant matter
___________ is sometimes referred to as “rose gardener’s disease” because infection can result from being pricked by thorns (and other plant material) contaminated with _________ _________.
Sporotrichosis is sometimes referred to as “rose gardener’s disease” because infection can result from being pricked by thorns (and other plant material) contaminated with *Sporothrix schenckii*.
The _____ form of Sporothrix schenckii appears as elongated _____-shaped cells on microscopy.
The yeast form of Sporothrix schenckii appears as elongated cigar-shaped cells on microscopy.
Describe the typical presentation of infection with Sporothrix schenckii (e.g. following a rosebush thorn scratch to the arm).
Subcutaneous nodules and ulcers
(due to ascending lymphadenopathy)
How do the subcutaneous nodules and ulcers associated with Sporothrix schenckii infection typically progress/arise?
Ascending lymphadenopathy
What medication type is typically used for infection with Sporothrix schenckii? Is it PO, IV, IM, topical, or sub-Q?
What is less commonly used?
Oral itraconazole;
saturated solutions of potassium iodide
