Chapter 6: Fungal & Protozoal Diseases Flashcards
candidiasis is caused by what fungus?
candida albicans
candidiasis exists in ___ forms; what are they?
- two forms (dimorphic)
- yeast form - innocuous
- hyphal form - invasion of host tissue
___ is by far the most common oral fungal infection in humans
candidiasis
up to ___% of people carry candida albicans in their mouth in health. what happens with age?
- 50%
- rate increases with age
candidiasis is mostly a ___ infection
opportunistic
however, healthy patients may develop infection
what are the 4 clinical patterns of candidiasis?
- pseudomembranus
- erythematous
- chronic hyperplastic
- mucocutaneous
what are 5 characteristics that can be present with erythematous candidiasis?
- median rhomboid glossitis
- chronic multifocal
- angular cheilitis
- denture stomatitis
- acute atrophic (antibiotic sore mouth)
what is the best recognized form of candidiasis?
pseudomembranous
aka thrush
what is the clinical presentation of pseudomembranous candidiasis?
- adherent white plaques that resemble cottage cheese
- removable - apply pressure with gauze
- underlying mucosa may be normal or erythematous
with pseudomembranous candidiasis, what should you be thinking if the underlying mucosa bleeds?
there is likely another process occurring (lichen planus)
what 3 things can pseudomembranous candidiasis be initated by?
- antibiotics: eliminates competing bacteria
- impairment of immune system: leukemic patients, HIV, infants
- asthma inhalers
what are the symptoms of pseudomembranous candidiasis?
- mild burning
- mild unpleasant taste
- *these may not always be present
what is the distribution of pseudomembranous candidiasis?
buccal mucosa, palate, and dorsal tongue
is there a white component in erythematous candidiasis?
no
erythematous candidiasis is commonly overlooked clinically
erythematous candidiasis is more common than what other type of candidiasis?
pseudomembranous
median rhomboid glossitis is also called ___
central papillary atrophy
does median rhomboid glossitis occur in adults or children?
it is a disease of adults
describe the clinical presentation of median rhomboid glossitis
- well-demarcated erythematous zone affecting the midline, posterior dorsal tongue
- anterior to the circumvallate papilla
- symmetrical
- surface may be smooth or lobulated
the erythema present in median rhomboid glossitis is due to ___
loss of filiform papilla
chronic multifocal candidiasis is median rhomboid glossitis plus what?
signs of infection at other sites
what are the other common sites of infection found in chronic multifocal candidiasis?
- hard and soft palate (“kissing lesion”)
- angles of the mouth (angular cheilitis)
angular cheilitis can be a component of ___, but usually occurs alone
chronic multifocal candidiasis
angular cheilitis is common in what people?
older patients with reduced vertical dimension
where is angular cheilitis found?
accentuated folds at the corners of the mouth where saliva can pool
describe the etiology of angular cheilitis
- 20% candidia albicans alone
- 20% staphylococcus areus alone
- 60% combination of both
angular cheilitis infection may more extensively involve the perioral skins, usually due to ___. what is the term for the clinical pattern?
- chronic lip picking
- clinical patterns is termed cheilocandidiasis
denture stomatitis is also termed ___
chronic atrophic candidasis
denture stomatitis is localized to ___
denture-bearing areas of a maxillary removable denture
is denture stomatitis symptomatic?
no, although it does have a striking clinical appearance
describe how denture stomatitis can develop
- patient wears denture continuously
- denture harbors most of the organism
what is the treatment for denture stomatitis?
need to treat both the soft tissues and the denture to prevent recurrence)
acute atrophic candidiasis is also called ___ and follows a course of ___
- antibiotic sore mouth
- broad-spectrum antibiotics
with acute atrophic candidiasis, what does the mouth feel like?
feels like hot liquid scalded it
what is the clinical presentation of acute atrophic candidiasis?
- diffuse loss of filiform papillae of dorsal tongue (appears bald)
- similar appearance symptomology is noted in xerostomia patients
chronic hyperplastic candidiasis is also called ___
candidal leukoplakia
___ candidiasis clinically presents as a white patch that cannot be removed
chronic hyperplastic candidiasis
___ is the least common form of candidiasis
chronic hyperplastic candidiasis
why is chronic hyperplastic candidiasis (aka candidal leukoplakia) controversial?
it’s a question of which comes first - leukoplakia or candidiasis?
where does chronic hyperplastic candidiasis commonly occur?
anterior buccal mucosa
pseudomembranous candidiasis
pseudomembranous candidiasis
erythematous candidiasis
median rhomboid glossitis
(erythematous candidiasis)
chronic multifocal candidiasis
(erythematous candidiasis)
angular cheilitis
(erythematous candidiasis)
denture stomatitis
(erythematous candidiasis)
denture stomatitis
chronic hyperplastic candidiasis
chronic hyperplastic candidiasis
acute atrophic candidiasis
autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED)
(form of mucocutaneous candidiasis)
mucocutaneous candidiasis is a rare group of ___
immunologic disorders
young patients with mucocutaneous candidiasis can develop what 3 things?
- endocrine-candidiasis syndrome
- autoimmune polyendocrineopathy-candidiasis-ectodermal dystrophy (APECED)
- 10% have malignancies such as oral or esophageal carcinoma
- iron-deficiency anemia
in mucocutaneous candidiasis cases, what do the oral lesions look like?
- white plaques that do not rub off
- similar to chronic hyperplastic candidiasis
What is the treatment for candidiasis?
antifungal agents
- nystatin
- amphotericin B
- imidazole agents - clotrimazole
describe the treatment of candidiasis using nystatin
- oral use as suspension or lozenge
- bitter taste, so sugar is added - don’t use in xerostomia-related candidiasis
- effectiveness depends on direct contact, so multiple daily doses are necessary
describe the treatment of candidiasis using amphotericin B
- IV treatment for life-threatening systemic fungal infections
discribe the treatment of candidiasis using clotrimazole
- one brand name is mycelex
- formulated as a troche (lozenge)
- effectiveness depends on direct contact, so multiple daily doses are necessary
- very few side effects
candidiasis should resolve easily following ___
antifungal therapy
if candidiasis infection recurs after treatment, what should you do?
investigate possible predisposing factors
___ is the most common systemic fungal infection in the US
histoplasmosis
what is histoplasmosis caused by?
histoplasma capsulatum
describe how histoplasma capsulatum is dimorphic
it is a yeast at body temperature in a human host, and a mold in the natural environment
where is histoplasma capsulatum found? where is it endemic? up to what percent of people living in these areas are infected?
- humid areas with soil enriched by bird or bat excrement
- it is endemic in the ohio and mississippi river valley
- 90% are infected
how is histoplasmosis spread?
airborne spores are inhaled, passed into the terminal passages of the lungs, where they germinate
___% of people who are infected with histoplasmosis have either no symptoms or such mild symptoms that the patient doesn’t seek medical care. what are the mild symptoms like, and how long can they last?
- 99%
- mild symptoms are flu-like and can last for 1-2 weeks
most patients who become exposed to histoplasmosis are ___ and inhale and ___ number of spores
- healthy
- small
in general, describe the patients who become infected with histoplasmosis
- older
- debilitated
- immunocompromised
- up to 10% of AIDS patients develop disseminated disease in endemic areas
most histoplasmosis oral leasions occur with the ___ form
disseminated
describe the clinical presentation of histoplasmosis oral lesions
- appears as a solitary, variably painful ulceration of several weeks duration
- ulcerated lesions have firm, rolled margins
- clinically indistinguishable from malignancy
- may appear erythematous or white with an irregular surface
the histopathology of histoplasmosis shows ___
granulomatous inflammation
what is the treatment for acute histoplasmosis?
- none or palliative care
what is the treatment for chronic histoplasmosis?
- require treatment despite the fact that 50% recover spontaneously
- pulmonary damage is progressive if untreated
- 20% succomb to untreated disease
- treatment of choice is IV amphotericin B, but can cause kidney damage
what is the treatment for disseminated histoplasmosis?
- 90% will succomb to disease if untreated
- amphotericin B is treatment of choice
candidiasis
histoplasmosis
blastomucosis
blastomycosis
blastomycosis
blastomycosis
blastomycosis
___ is 10x less common than histoplasmosis
blastomycosis
what causes blastomycosis?
blastomyces dermatidis
describe how blastomyces dermatitidis is dimorphic
- grows as yeasts at body temperature
- grows as mold in rich, moist soil
where is blastomyces dermatitidis found?
in eastern areas of the US and into canada
what is the male:female ratio of the prevalence of blastomycosis, and what is it likely due to?
- 9:1 male:female
- likely due to a greater degree of outdoor activity in med where the organisms grow
is the occurance of blastomycosis in immunocompromised patients common or rare?
rare
how is blastomycosis acquired?
inhalation of spores after a rain; spores grow in alveoli of lungs
acute blastomycosis symptoms resemble ___
pneumonia
chronic blastomycosis symptoms resemble ___
tuberculosis
blastomycosis oral lesions result from ___ or ___
extrapulmonary dissemination or local inoculation
describe the clinical presentation of blastomycosis oral lesions
- lesions may be irregulat with an erythematous or white surface
- pesions may appear as ulcerations with irregular rolled borders with variable degrees of pain
- all oral lesions are indistinguishable from SCCA clinically
blastomycosis infection can induce a benign reaction of the epithlium termed ___. what does it look like to the untrained eye?
- pseudoepitheliomatous (pseudocarcinomatous) hyperplasia
- looks like cancer
paracoccidioidomycosis (south american blastomycosis)
what causes paracoccidioidomycosis?
paracoccidioides brasiliensis
what is a host of paracoccidioides brasiliensis?
nine-banded armadillo
what is the male:female ratio of paracoccidioiomycosis?
15:1 male:female
most patients infected with paracoccidioidomycosis are employed in ___
agriculture
what is the treatment of paracoccidioidomycosis?
it is generally self-limiting
what is the histology of paracoccidioidomycosis?
granulomatous inflammation (characterized by collections of macrophages and multinucleated giant cells)
describe the histologic appearance of paracoccidioides brasiliensis
the organism often shows multiple daughter buds on the parent cell, resulting in an appearance described as resembling “mickey mouse” or the spokes of a ship’s steering wheel (“mariner’s wheel”)
___ infection is thought to be attributable to a protective effect of female hormones (because beta-estradiol inhibits the transformation of the hyphal form of the organism to the pathogenic yeast form)
paracoccidioides brasiliensis
coccidioidomycosis is also called ___
san joaquin valley fever
what causes coccidioidomycosis?
coccidioides immitis
coccidioides immitis is a ___ organism
- saprophytic (lives on dead/decaying organic matter)
- it is also dimorphic
describe how coccidioides immitis is dimorphic
- mold in natural environment
- yeast in infected host tissues
how is coccidioidomycosis spread?
athrospores are produced by the mold, become airborne, and can be inhaled
what are the endemic areas where coccidioides immitis is found?
southwestern US and mexico
___% of people with coccidioidomycosis are asymptomatic
60%
occasionally, patients with coccidioidomycosis may have a hypersensitivity reaction which causes the development of ___ or ___
- erythema multiforme-like cutaneous reaction or erythema nodosum
describe erythema nodosum which can be a result of coccidioidomycosis
- affects the legs and is characterized by multiple painful inflammatory nodules
- this reaction occurring in conjunction with coccidiodomycosis is termed valley fever
coccidioidomycosis
cryptococcosis
cryptococcosis is caused by ___
cryptococcus neoformans
cryptococcus neoformans lives in ___
pigeon excrement
cryptococcus neoformans grows in ___
yeast in both the soil and infected tissue
what does cryptococcus neoformans have that protects it from host defenses?
prominent mucopolysaccharide capsule
is the primary infection of cryptococcosis symptomatic or asymptomatic?
asymptomatic
most patients diagnosed with cryptococcosis have ___
- immune suppression
- 10% of AIDS pts will acquire this infection
- dissemination is common in immunocompromised patients
where is the most frequent site of involvement for disseminated cryptococcosis?
meninges
zygomycosis is also called ___
mucormycosis
zygomycosis is found on ___
decaying organic material
which form of zygomycosis is most important to oral health care providers?
rhinocerebral form
what can enhance the growth of zygomycosis?
iron
which patients are at risk for zygomycosis infection?
- diabetic patients who are uncontrolled (ketoacidosis inhibits iron binding to transferrin, allowing serum iron levels to rise)
- patients taking deferoxamine (iron-chelating agent)
- immunocompromised patients
what are the presenting symptoms of rhinocerebral zygomycosis?
- nasal obstruction
- bloody nasal discharge
- facial pain and headache
- facial swelling/cellulitis
- visual disturbances/proptosis
what can result from untreated zygomycosis, and how does it appear?
massive tissue destruction, which appears black and necrotic
what is the treatment for zygomycosis?
- radical surgical debridement
- high doses of amphotericin B
___% of patients with rhinocerebral zygomycosis succumb to their disease
60%
zygomycosis aka mucormycosis
aspergillosis
aspergillosis
mass has undergone dystrophic calcification, forming an antrolith
describe the noninvasive form of aspergillosis
- affects a normal host
- allergic reaction affecting the sinuses (allergic fungal sinusitis)
- large mass of fungal hyphae is called an aspergilloma
describe the invasive form of aspergillosis
- localized can occur in a normal host
- extensive involvement in immunocompromised patients
where is aspergillosis found?
worldwide
what are the two most common fungal infections worldwide?
- candidiasis (most common)
- aspergillosis (second in frequency to candidiasis)
what are the two most common species that cause aspergillosis?
a. fumigatus (90% of infections) and a. flavus
in aspergillosis, if the aspergilloma mass undergoes dystrophic calcification, what does it form, and how can it be visualized?
- antrolith
- can be visualized via xray
what is the treatment for noninvasive aspergillosis in an immunocompetent patient?
surgical debridement
what is the treatment for allergic fungal sinusitis?
surgical debridement and corticosteroids
what is the treatment for locally invasive aspergillosis in an immunocompetent patient?
debridement and antifungals
