7 Fungal Infections Flashcards
organism that causes candidiasis
Candida albicans
a normal component of the oral microflora in 30-50% of the population
Candida albicans
the most common ORAL fungal infection in humans
candidiasis
not just an opportunistic infection!! develops in people who are otherwise healthy too
candidiasis
Three main factors that determine whether a candidiasis infection will occur:
1) immune status of pt
2) pt’s oral mucosal environment
3) pt’s particular strain of C. albicans
predisposing factors to candidiasis infection (5)
- antibiotic use
- wearing a denture or appliance
- steroid inhaler use
- xerostomia
- immunosuppression
clinical patterns of candidiasis (4)
pseudomembranous candidiasis
erythematous candidiasis
angular cheilitis
chronic hyperplastic candidiasis
Name the candidiasis infection: aka thrush
pseudomembranous
Name the candidiasis infection: white plaques resembling cottage cheese that adhere to the oral mucosa
pseudomembranous
White plaques characteristic of pseudomembranous candidiasis consist of (3)
fungal hyphae, epithelial cells, and debris
Name the candidiasis infection: plaques CAN be scraped off, underlying mucosa may appear normal or erythematous
pseudomembranous
most common locations of pseudomembranous candidiasis
buccal mucosa, palate, dorsal tongue
Name the candidiasis infection: symptoms are mild (if present at all), unpleasant taste
pseudomembranous candidiasis
Common causes/situations of pseudomembranous candidiasis (4)
- recent broad-spectrum antibiotic
- impairment of the patient’s immune system
- infants (underdeveloped immune system)
- steroid inhalers for asthma
Name the candidiasis infection: very common but overlooked clinically
erythematous candidiasis
Several sub-categories of erythematous candidiasis:
- dorsal tongue (acute atrophic candidiasis, central papillary atrophy)
- palate
- denture stomatitis
Name the candidiasis infection: • focal redness and loss of the filiform papillae on the midline and posterior dorsal tongue • chronic and asymptomatic • usually somewhat symmetric • smooth surface
central papillary atrophy (median rhomboid glossitis)
Name the candidiasis infection:
• aka “antibiotic sore mouth”
• typically occurs after broad-spectrum antibiotic therapy
acute atrophic candidiasis (erythematous candidiasis)
Name the candidiasis infection:
• pts complain that their mouth feels like they have “scalded” it
• diffuse loss of the filiform papillae on the dorsal tongue, while tongue looks red and smooth
acute atrophic candidiasis (erythematous candidiasis)
Name the candidiasis infection: erythema localized to the denture-bearing mucosa, may have petechial hemorrhages, usually asymptomatic
denture stomatitis (erythematous candidiasis)
Name the candidiasis infection: true candidal infection or just tissue response to microorganisms embedded in the denture acrylic? cultures usually show heavy colonization of the denture but not of the mucosa, consider the possibility of allergy or inadequately cured acrylic
denture stomatitis (erythematous candidiasis)
Name the candidiasis infection: erythema, cracking, and fissuring at the corners of the mouth
angular cheilitis
Angular cheilitis can occur in anyone, but especially in patients with?
decreased VDO—saliva pools in the accentuated folds keeping them moist
Angular cheilitis may be a combined infection:
20% C. albicans alone
20% Staph aureus alone
60% C. albicans and Staph aureus together
- extension of angular cheilitis to involve the perioral skin
- erythema, crusting, exfoliation, and swelling of the lips
- associates with actions or habits that keep the lips and perioral skin moist
cheilocandidiasis
actions/habits that keep the lips/perioral skin moist and cause cheilocandidiasis (2)
- chronic lip licking or sucking, thumb sucking
* chronic use of lip balms
Name the candidiasis infection: an uncommon form of candidiasis, often speckled red/white in appearance
chronic hyperplastic candidiasis
MC location of chronic hyperplastic candidiasis
anterior buccal mucosa (near commissures)
Name the candidiasis infection: CANNOT be scraped off!!!
chronic hyperplastic candidiasis
Name the candidiasis infection: should resolve completely after antifungal therapy
chronic hyperplastic candidiasis
dx of candidiasis (4)
- clinical presentation may be characteristic
- culture (Sabouraud’s agar slant)—organisms grow white colonies
- exfoliative cytology—stained with PAS method
- biopsy—hyphae are embedded in the parakeratin layer and induce a neutrophilic inflammatory infiltrate
tx of candidiasis
- appropriate antifungal medications (nystatin, clotrimazole, fluconazole)
- a patient’s dentures must be treated in addition to their mucosa
Tx for pseudomembranous and erythematous candidiasis? Angular cheilitis and cheilocandidiasis? Complete dentures? Partial dentures?
- Pseudomembranous and erythematous candidiasis—nystatin, clotrimazole, fluconazole
- Angular cheilitis and cheilocandidiasis—clotrimazole cream 1%
- Complete dentures (no metal)—diluted bleach
- Partial dentures (with metal)—nystatin
Disp: 11
Sig: take 2 tablets on day 1, then 1/day until gone
Note: compliance is usually better compared to clotrimazole
Drug interactions: oral hypoglycemics, phenytoin, coumadin
fluconazole (100 mg tablets)
drug interactions of fluconazole
oral hypoglycemics, phenytoin, coumadin
Disp: 50
Sig: dissolve one in mouth 5x/day until gone
Note: effectiveness depends on direct contact with the mucosa (must be dissolved, won’t work if chew/swallow)
Drug interactions: won’t interact with other meds, more expensive than fluconazole
clotrimazole (10 mg oral troches)
Disp: 480 mL
Sig: use 2 tsp as a mouth rinse 5 qd for 10 days, hold suspension in mouth for 2 min then expectorate
Note: effectiveness depends on direct contact with mucosa, bitter taste of drug is disguised by sugary flavoring agents so may not be the best choice for pts with high caries risk
nystatin oral suspension 100,000 units/mL (for oral mucosa)
Disp: 250 mL
Sig: soak partial denture overnight for 10 days, refresh suspension every 3 days
nystatin oral suspension for partial denture (100,000 units/mL)
how to dilute bleach for complete denture
one tablespoon of bleach in 1 cup water, soak overnight for 10 days (make sure to rinse thoroughly before inserting back in mouth to avoid chemical irritation!!)
available OTC, marketed as athlete’s foot cream, apply to affected areas 3-4 times per day for 10 days to treat angular cheilitis/cheilocandidiasis
clotrimazole cream 1%
organism that causes histoplasmosis
Histoplasma capsulatum
the most common SYSTEMIC fungal infection in the US (500,000 new cases/yr)
histoplasmosis
suited to growth in humid areas
Histoplasma capsulatum
organisms common in bird and bat droppings
Histoplasma capsulatum
endemic to the Ohio and Mississippi river valleys, 80-90% of the population in endemic areas has been infected
Histoplasma capsulatum (histoplasmosis)
no person-to-person transmission, spores are inhaled from the environment then germinate into yeasts inside the lungs
Histoplasma capsulatum (histoplasmosis)
Expression of histoplasmosis depends on (3):
- amount of spores inhaled
- immune status of patient
- strain of Histoplasma capsulatum
Name the type of histoplasmosis: a common, self-limited pulmonary infection
acute
Name the type of histoplasmosis: the type that normal, healthy people get if they inhale a high concentration of spores
acute
Name the type of histoplasmosis: calcification of hilar lymph nodes may be seen incidentally on chest films in the future
acute histoplasmosis
Name the type of histoplasmosis: flu-like clinical presentation (for about 2 weeks)—fever, headache, body ache, non-productive cough
acute
Name the type of histoplasmosis: much less common, also affects the lungs
chronic
Name the type of histoplasmosis: typically occurs in older, emphysematous or immunocompromised patients
chronic
Name the type of histoplasmosis: TB-like clinical presentation—fever, chest pain, dyspnea, cough, hemoptysis, fatigue
chronic
Name the type of histoplasmosis: the least common type
disseminated
Name the type of histoplasmosis: infection spreads to extrapulmonary sites
disseminated
Name the type of histoplasmosis: old, debilitated, or immunocompromised pts
disseminated
Name the type of histoplasmosis: oral cavity can be affected—a solitary, variably-painful ulcer with firm, rolled borders (mimics malignancy)
disseminated
Oral appearance: a solitary variably-painful ulcer with firm, rolled borders (mimics a malignancy)
disseminated histoplasmosis
dx of histoplasmosis
- culture
- serologic testing for H. capsulatum antibodies
- biopsy specimen—granulomatous inflammation, organisms can usually be seen on H&E slides but are better visualized with special stains such as GMS or PAS
Tx of acute histoplasmosis? Chronic? Disseminated?
- Acute—no tx other than supportive care
- Chronic—IV amphotericin B for immunocompromised pts, itraconazole for non-immunosuppressed patients (fewer side effects)
- Disseminated—IV amphotericin B, followed by intraconazole for several months
Prognosis of acute histoplasmosis? Chronic? Disseminated?
- Acute—excellent
- Chronic—20% mortality rate amongst untreated pts, amphotericin B can cause kidney damage
- Disseminated—80-90% mortality rate in untreated pts, 7-23% mortality rate among treated patients
organism that causes blastomycosis
Blastomyces dermatitidis
overlaps same region as histoplasmosis, but also extends further north
blastomycosis
Which is more common? histoplasmosis or blastomycosis
histoplasmosis is 10x more common
male predilection? vs population bias
blastomycosis
spores are inhaled from the environment, infection usually limited to the lungs, relatively rare in immunocompromised pts
blastomycosis
acute vs chronic blastomycosis
Acute—resembles pneumonia
Chronic—resembles TB (more common than acute)
If dissemination of blastomycosis occurs, ________ is usually involved.
skin
oral lesions may represent dissemination or local inoculation
blastomycosis
tx for blastomycosis
itraconazole for mild to moderate cases, amphotericin B for severe cases
organism that causes coccidioidomycosis
Coccidioides immitis
grows in semiarid, desert soil (arthrospores)
coccidioidomycosis
endemic to southwestern US and Mexico, estimated 100,000 infections per year in the US
coccidioidomycosis
- acute infection is asymptomatic in 60% of cases
* 40% develop flu-like symptoms about 1-3 weeks after inhaling the arthrospores
coccidioidomycosis
a hypersensitivity response to a coccidioidomycosis infection, resembles erythema multiforme or erythema nodosum
“valley fever”
immunosuppression greatly increases the risk of dissemination
coccidioidomycosis
common extrapulmonary infection location of coccidioidomycosis
skin (central face, nasolabial fold area)
intraoral lesions are uncommon
coccidioidomycosis and cryptococcosis
tx for coccidioidomycosis
amphotericin B for immunosuppressed, dissemination, and severe lung infection
organism that causes cryptococcosis
Cryptococcus neoformans
worldwide distribution, uncommon in healthy persons, infection can be devastating for an immunocompromised pt
cryptococcosis
organism lives in pigeon droppings, spreads via inhalation of spores
cryptococcosis
dissemination is common in immunocompromised patients, meninges is most common site of involvement (uncommon in oral cavity)
cryptococcosis
headache, fever, vomiting, neck stiffness—initial signs of infection in may pts
cryptococcal meningitis
80% of pts diagnosed with disseminated cryptococcosis have ?
AIDS
first and second most common site of dissemination of cryptococcosis
1) meninges
2) skin
tx of cryptococcosis
combination antifungal therapy including amphotericin B
formerly the most common life-threatening fungal infection in AIDS pts, has become much less of a problem since the advent of ART (antiretroviral therapy), still a major cause of death worldwide in countries where pts cannot afford ART, estimated 5-10% of AIDS pts will get this
cryptococcosis
organisms that cause mucormycosis (zygomycosis)
Mucor, Absidia, Rhizomucor Rhizopus genera (worldwide distribution)
a severe and sudden opportunistic infection, seen especially in uncontrolled insulin-dependent diabetics who are ketoacidotic (causes elevated iron serum levels which enhances the growth of these fungi)
mucormycosis (zygomycosis)
almost never occurs in healthy individuals
mucormycosis (zygomycosis)
mucormycosis (zygomycosis) can involve several areas of the body, but _________ form is most relevant to DDS
rhinocerebral
Initial symptoms may include:
• nasal obstruction or bloody discharge
• facial pain, headache
• facial swelling or cellulitis
• swelling and ulceration of palate or maxillary alveolus
• visual changes, facial paralysis
• radio graphic opacification of the maxillary sinus
rhinocerebral mucormycosis
ulcerated surfaces appear necrotic and black, massive tissue destruction can occur
rhinocerebral mucormycosis
dx of mucormycosis
biopsy—organisms tend to invade small blood vessels, infarction and extensive necrosis, large hyphae that tend to branch at 90 degree angles
biopsy reveals large hyphae that tend to branch at 90 degree angles
mucormycosis
tx of mucormycosis
radical surgical debridement of necrotic tissue, high dose IV amphotericin B, control pt’s underlying systemic disease
- poor prognosis—40-50% mortality rate
* survivors have functional and cosmetic issues related to tissue defects
mucormycosis
palatal obturation
mucormycosis
organism that causes aspergillosis
Aspergillus fumigatus or A. flavus (worldwide distribution, inhalation of spores)
non-invasive vs invasive forms of aspergillosis
- non-invasive form usually occurs in healthy pt
* invasive form usually occurs in immunosupressed pts (AIDS, transplant pts, uncontrolled diabetics)
can be acquired in the hospital (nosocomial infection), especially if construction is going on which stirs up spores
aspergillosis
Invasive or non-invasive aspergillosis? healthy pt
non-invasive
Invasive or non-invasive aspergillosis? may manifest as allergic fungal sinusitis, affects the sinuses or bronchopulmonary tract
non-invasive
Invasive or non-invasive aspergillosis? may manifest as an aspergilloma—fungus ball, mass of fungal hyphae in the maxillary sinus
non-invasive
a mass of fungal hyphae in the maxillary sinus
aspergilloma
Invasive or non-invasive aspergillosis? may occur after maxillary or molar extraction or endo tx, predisposes overlying sinus to infection
non-invasive
Invasive or non-invasive aspergillosis? immunocompromised pt
invasive
Invasive or non-invasive aspergillosis? a relatively uncommon location, gingival sulcus point of entry?, painful gingival ulceration and diffuse gray or purple swelling
invasive—oral invasive aspergillosis
Invasive or non-invasive aspergillosis? starts in the lungs (chest pain, cough, fever) —> enters bloodstream and can spread almost anywhere
invasive—disseminated aspergillosis
Tx for aspergilloma? Allergic fungal sinusitis? Invasive aspergillosis?
- Aspergilloma—surgical debridement
- Allergic fungal sinusitis—surgical debridement and systemic corticosteroids
- Invasive aspergillosis—aggressive debridement and systemic voriconazole
3 manifestations of non-invasive aspergillosis:
allergic fungal sinusitis
aspergilloma
after max molar extraction or endo tx
