Mycetoma and other Subcutaneous Mycoses Flashcards
Fungal infections involving the dermis, subcutaneous tissues, and muscle and may extend to bone.
Subcutaneous mycoses
Subcutaneous mycoses are initiated by ________ to the skin.
trauma
Fungal infections involving the ________, ________________, and __________ and may extend to ________.
dermis
subcutaneous tissues
muscle
bone
Difficult to treat and surgical intervention is frequently employed.
Subcutaneous mycoses
It is a chronic, granulomatous disease of the skin and subcutaneous tissue, which sometimes involves muscle and bones.
Mycetoma
Mycetoma is characterized by _________, ____________, and _______________ that exude characteristic grains of clumped organisms.
swelling
abscess formation
multiple draining sinuses
Mycetoma typically affects the ____________, but also other areas of the body like ______, ______, and _______.
lower extremities
hand
back
neck
Mycetoma was first described in the ____________ of _________.
Madura district (Madura foot)
India
Mycetoma is endemic in?
tropical, subtropical, and temperate regions
Mycetoma is endemic in these places:
Sudan
Senegal
Somalia
India
Pakistan
Mexico
Venezuela
Mycetoma is more common in men or women?
Men
Mycetoma is common in men than in women with a ratio of?
3:1
Mycetoma is common in people who work in _________ as ________.
rural areas
farmers
Why are men more affected by mycetoma than women?
Since men usually work as farmers, this infection is most likely caused by trauma to the skin which is why they are more prone than women.
Mycetoma is acquired via _______________.
trauma of the skin
During trauma,
1. ________ subcutaneous firm _______ is observed.
2. massive swelling with skin rupture and _____________.
3. old sinuses close and new ones open, draining exudates with _______.
painless
nodule
sinus tract formation
grains (granules)
Mycetoma is classified as ___________ and ____________.
Eumycetoma
Actinomycetoma
It is caused by a several mould (filaments) fungi.
Eumycetoma
It is caused by aerobic filamentous bacteria gram positive.
Actinomycetoma
Most common eumycetoma
Madurella mycetomatis
Madurella grisea
Pseudallescheria boydii
Most common actinomycetoma
Actinomadura madurae
Streptomyces somaliensis
Nocardia brasiliensis
Color of grains in eumycetoma
Black/white
Color of grains in actinomycetoma
Yellow
White
Yellowish-brown
Pinkish-red
What color is not present in actinomycetoma?
Black
Clinical samples in mycetoma:
Biopsy tissue
Pus with grains
Blood
This type of biopsy is more accurate as clinical sample since superficial samples of the draining sinuses are inadequate.
Deep biopsy
This clinical sample is only used for serology.
Blood
In direct microscopic examinationof mycetoma, what are observed in grains?
size of the filaments
color
What is the color of grains that indicate P. boydii, Nocardia spp., or A. madurae infection.
White-yellow
What color of grains that indicate Madurella spp. infection?
Black
Culture media used for mycetoma to isolate fungi.
Sabouraud dextrose agar (SDA)
For ____________, biochemical and other tests are used for identification.
Actinomycetes
Why is deep biopsy more accurate than a superficial biopsy?
Because the superficial layer of the skin may contain mixed microbe at least the normal flora.
__________ is suggested for several months or years.
Therapy
Eumycetoma or actinomycetoma: which respond better to treatment?
Actinomycetoma
This test is used if bone involvement is suspected.
Radiologic tests
Treatment for eumycetoma
Itraconazole
Treatment for actinomycetoma
Trimethoprim-sulfamethoxazole
Treatment for actinomycetoma is trimethoprim-sulfamethoxazole with either _______ or __________.
dapsone
streptomycin
Dapsone is more common and is required to be given _________.
Intravenously
It is a chronic localized firm subcutaneous masses.
Subcutaneous zygomycosis
Subcutaneous zygomycosis typically affects the:
facial area
hand
arm
leg
thigh
Characteristic feature of subcutaneous zygomycosis
Necrosis
What differentiates subcutaneous zygomycosis from mycetoma?
No abscess or sinuses
Subcutaneous zygomycosis is acquired via ____________________, needle-stick, tattooing, contaminated surgical dressings, and burn wound.
traumatic implantation of spores
____________ (acute) subcutaneous zygomycosis caused by __________, ____________.
Mucorales
Rhiceos
Mucos
_____________ (chronic) subcutaneous zygomycosis caused by ____________, _______________.
Entomophthorales
Conidiobolus coronatus
Basidiobolus ranarun
Direct microscopy for subcutaneous zygomycosis, in stained sections/smears:
Broad non-septate hyphae
Treatment for subcutaneous zygomycosis
Amphotericin B
Is a group of fungal infections caused by dematiaceous (darkly pigmented) fungi widely distributed in the environment.
Phaeohyphomycosis
Presents as nodules or erythematous plaques with no systematic involvement
Phaeohyphomycosis
Affected sites for phaeohyphomycosis
Thigh
Legs
Feet
Arms
Phaeohyphomycosis shows _____ septate fungal hyphae.
brown
Why does direct microscopy of phaeohyphomycosis shows brown septate fungal hyphae?
Because it is caused by dematiaceous which are darkly pigmented fungi.
Clinical specimens used for phaeohyphomycosis?
Pus
Biopsy tissue
Treatment of choice for phaeohyphomycosis?
Surgical excision of the lesion
It is a subcutaneous, deep cutaneous or systemic fungal infection.
Sporotrichosis
Sporotrichosis can present as:
Plaque
Lymphanginitic
Dissiminated
Dimorphic fungus
Sporothrix schenckii
Finger-like yeast cells or cigar shaped
Sporotrichosis
Treatment of sporotrichosis
Itraconazole
Potassium Iodide
Obligatory parasitic fungus of rhinosporidiosis
Rhinosporidium seeberi
Obligatory parasitic fungus of lobomycosis
Lacazia loboi
Spherules with endospores
Rhinosporidiosis
Muriform cells (sclerotic bodies)
Chromoblastomycosis
Chains of yeast cells
Lobomycosis
Uncommon and not as isolated clinical problem
Bone and joint infections
