24 - 162 - DEEP FUNGAL INFECTIONS Flashcards
asteroid body may be seen in what condition?
Sprotrichosis
this nontuberculous mycobacterial infection closely resembles lymphangitic sporotrichosis.
Mycobacterium marinum (fish-tank granuloma)
treatment options for sporotrichosis
- traconazole 200 mg once daily
- Terbinafine 200 mg once daily
*treatment continued until 1 week after clinical resolution - Saturated solution of potassium iodide (SSKI), 4 to 6 mL thrice daily × 3 to 4 weeks
mycetomas caused by fungi are known as
Eumycetoma
mycetomas caused by bacteria are known as
actinomycetoma
in mycetoma grains,** Black or dark grains** are always produced by what?
fungi
in mycetoma grains, Red grains are always produced by what?
actinomycetes (bacteria)
in mycetoma grains, pale (white) grains may be produced by what?
either fungi or actinomycetes
causative agents of Mycetoma (maduromycosis, Madura foot)
Treatment options for eumycetoma
- Ketoconazole 200 mg
- Itraconazole 200 mg
- Voriconazole 200 to 400 mg daily × several months
treatment options for Actinomycetoma:
- Dapsone + streptomycin
- Sulfamethoxazole-trimethoprim + rifampin or streptomycin
chronic fungal infection of the skin and subcutaneous tissues caused by pigmented (dematiaceous) fungi that are implanted into the dermis from the environment
Chromoblastomycosis
most common causative agents of Chromoblastomycosis
- Fonsecaea pedrosoi
- Cladophialophora carrionii
- The initial site of the infection is usually on the feet, legs, arms, or upper trunk. The clinical features vary.
- The initial lesion is often a warty papule that expands slowly over months or years
Chromoblastomycosis
- The typical **sclerotic or muriform fungal cells **can be seen in skin scrapings taken from the surface of lesions where there is a small, dark spot on the skin surface, using KOH mounts
- In culture, these fungi are very similar in gross macroscopic appearance, producing** black colonies with a downy surface.**
Chromoblastomycosis
- rare infection characterized by the formation of subcutaneous inflammatory cysts or plaques.
- caused by dematiaceous fungi, the most common of which are Exophiala jeanselmei and** W. dermatitidis,**
- these organisms form short, irregular, pigmented hyphae in tissue
- cyst wall consists of palisades of macrophages and other inflammatory cells surrounded by a** fibrous capsule,** and the fungal hyphae are found in the macrophage zone.
PHAEOHYPHOMYCOSIS/ PHAEOMYCOTIC CYST/ CYSTIC CHROMOMYCOSIS
causative agent of lobomycosis
Lacazia loboi
chief opportunistic systemic mycoses seen in humans
systemic or deep candidiasis, aspergillosis, and systemic zygomycosis
patient with diabetes mellitus are predisposed to what systemic mycoses?
Mucormycosis
patient who underwent abdominal sugery are predisposed to what systemic mycoses?
Candidiasis
patient who underwent heart valve sugery are predisposed to what systemic mycoses?
Various but mainly Candida albicans and non-albicans Candida sp.
- The fungus can be found in KOH mounts of pus, skin scrapings, or sputum as thick-walled, rounded, refractile, spherical cells with broad-based buds
- In culture, the fungus grows as a mycelial fungus at room temperature.
- It produces small, rounded, or pear-shaped conidia.
Blastomycosis
most common clinical type of coccidioidomycosis
primary pulmonary form
antigen obtained from spherules of C. immitis and may be better than coccidioidin for detecting sensitization
Spherulin
- Sputum, exudates, and scrapings can be screened using KOH.
- They show numbers of round yeasts with a characteristic form of multiple budding in which a parent cell is surrounded by large numbers of smaller buds.
PARACOCCIDIOIDOMYCOSIS
Patients with AIDS, as well as those receiving what biologic therapy, appear to be particularly susceptible penicilliosis?
rituximab
In culture, this presents with a **green or grayish mold **that produces typical conidiophores and a diffusible red pigment
Talaromyces marneffei
most common clinical manifestation of cryptococcosis
meningoencephalitis
Cryptococci are large (5 to 15 µm in diameter), budding cells with capsules that are best observed by what examination?
direct microscopy of India ink or Nigrosin mounts
What fungal infection has cigar-shaped or oval yeasts may, be surrounded by a thick, radiating eosinophilic fringe forming an asteroid body
Sporotichosis
2.A cheaper alternative, effective treatment for cutaneous Sporotrichosis with hyper salivation and nausea as side effects
Potassium iodide (saturated solution)
Complications such as elephantiasis and Squamous cell Ca can occur in this infection
Chromoblastomycosis (Chromomycosis)
Characterized by keloid-like skin lesions on exposed sites with surgical removal as the only main treatment
Lobomycosis (Keloidal Blastomycosis, Lobo Disease)
Its early infection starts in the inferior turbinates of the nose then spreads to the central part of the face causing deformities of the nose lips
and cheeks
Conidiobolomycosis
Characterized by polyps studded with white flecks affecting mucous membranes
Rhinosporidiosis
What pathogen produces small, rounded, or pear-shaped conidia
Blastomyces dermatitidis
This infection is predominant in males due to the presence of a cytoplasmic estrogen receptor on the fungus, and, in vitro, estradiol
suppresses the conversion of mycelium to yeast
Paracoccidioidomycosis (South American Blastomycosis, Paracoccidioidal Granuloma)
AIDS pxs with this infection have multiple skin lesions, which are umbilicated papules that may enlarge and ulcerate w/c are scattered on
the face and trunk
Infections caused by Talaromyces Marneffei (Penicilliosis, Penicilliosis Marneffei)
**Acneiform papules **or pustules progressing to warty or vegetating, crusted plaques, ulcers, and hard infiltrated plaques or nodules are
characteristic of widespread systemic infection
Cryptococcosis
Mucicarmine or Alcian blue can stain capsules of its cells
C. neoformans
Presents as large necrotic lesions such as ecthyma gangrenosum, but smaller papules and cold abscesses can occur and laboratory
detection of Galactomannan can confirm its diagnosis
Aspergillosis
Caused by filamentous bacteria that form large granules (sulfur granules) in abscess cavities and draining sinuses
Actinomycosis
