Fungal Infections

Question 1

Candida Albicans

Very common dimorphic yeast

_ form – commensal

_form – pathogen

ability of the yeast to undergo transformation to hyphal form under appropriate conditions, producing germinative or “germ” tubes

Answer 1

yeast form – commensal

hyphal form – pathogen

Question 2

Whether candidiasis develops, and the severity of the disease itself, appears to depend on at least three factors

Answer 2

The host immune status

The oral mucosal environment

The virulence of the candidal strain

Question 3

spectrum of Candida infection

_ state
_
localized invasive candidiasis and disseminated candidiasis uncommon

Answer 3

carrier state

superficial oral mucosal/cutaneous infection

Question 4

oral candidiasis presentations

_ _ _

Answer 4

pseudomembranous candidiasis

erythematous candidiasis

hyperplastic candidiasis

Question 5

_ Candidiasis
White, curdled milk or cottage cheese-like plaques; can be wiped-off

 Common sites: buccal mucosa, palate or tongue

 May be asymptomatic, but burning or unpleasant taste occasionally noted

Answer 5

Pseudomembranous Also known as “thrush”

not the most common but the most recognized

removable white plaque
Underneath the plaque - only invade very superficial
Underneath epi is okay - might be a little erythrothema

Question 6

_candidiasis

area of redness, variable borders

 tongue (posterior dorsal) is common site; may involve palate, oral commissures, perioral skin

Answer 6

Erythematous candidiasis

Acute atrophic candidiasis (“antibiotic sore mouth”)  Central papillary atrophy  Denture stomatitis?  Angular cheilitis  Perioral candidiasis  Chronic multifocal candidiasis

Question 7

_candidiasis

diffuse atrophy of dorsal tongue papillae, particularly after broad-spectrum antibiotics

acute onset

typically associated with “burning” sensation

Answer 7

Acute atrophic candidiasis aka “antibiotic sore mouth”

Become smooth and flat - as papilla become atrophic - goes from whitish to ball red surface of tongue

Question 8

Probably referred to as “median rhomboid glossitis” in the past

 Most are due to chronic candidiasis

 Well-defined area of redness, mid-posterior dorsal tongue

 Usually asymptomatic

Answer 8

Central Papillary Atrophy candidiasis

Question 9

Often referred to as “chronic atrophic candidiasis”
 Not much evidence to support this concept
 Denture is often contaminated with candidal organisms, but no invasion of mucosa is seen
 Erythema of palatal denture-bearing area - typically asymptomatic

Answer 9

Denture Stomatitis

Question 10

Usually related to candidiasis, but may have other cutaneous bacterial microflora admixed
 Redness, cracking of corners of mouth
 Often waxes and wanes
 Typically responds well to topical antifungal therapy

Answer 10

Angular Cheilitis

Question 11

Often associated with lip-licking or chronic use of petrolatum-based materials
 Usually related to candidiasis, but may have other cutaneous bacterial microflora admixed
 Redness, cracking of cutaneous surface

 Typically responds well to topical antifungal therapy

Answer 11

Perioral Candidiasis

looks like red lipstick all over

Question 12

Patient will have angular cheilitis, central papillary atrophy and a “kissing lesion” of the posterior hard palate

Answer 12

Chronic Multifocal Candidiasis

Question 13

_ Candidiasis

Also known as “candidal leukoplakia”
 White patch that cannot be rubbed off
 Uncommon; generally anterior buccal mucosa
 May be problematic because a true leukoplakia may have candidiasis superimposed on it
 Should resolve with antifungal therapy

Answer 13

Hyperplastic Candidiasis

less common clinically

Question 14

rare candidal infection

associated with specific immunologic defects related to how the body interacts with Candida albicans

Answer 14

Chronic Mucocutaneous Candidiasis

Question 15

rare candidal infection

seen in situations of severe uncontrolled diabetes mellitus or immune suppression

Answer 15

Invasive Candidiasis

Question 16

how to Dx Candidiasis

Answer 16

Sometimes clinical signs and symptoms are sufficient

 Culture - may not distinguish between carrier and infection

 Exfoliative cytology

 Biopsy - usually not necessary

Question 17

Histopathologic Features

 Variable host response to the organism
 Microabscesses may be seen in the superficial epithelium
 Chronic inflammation of the C.T.
 Acanthosis is often present
 In almost all cases, the candidal hyphae never penetrate deeper than the keratin layer

Answer 17

Candidasis infection

acanthosis - increased thickness of epi

Question 18

Px of candidiasis infection

Answer 18

In general, oral candidiasis is a nuisance that may present in normal patients, patients who have localized predisposing oral conditions, or immunosuppressed patients

 Good prognosis in normal patients

 Fair to poor prognosis, depending on degree of immune suppression

Question 19

Candidiasis - Treatment ?

Answer 19

Depends on the severity of the infection

 Superficial oral mucosal infections can usually be treated with one of the milder topical or systemic antifungal agents

 Life-threatening infections usually require intravenous amphotericin B

Question 20

Imidazole antifungal agent
 No significant systemic absorption or side effects
 Pleasant-tasting lozenges (troches)
 Disadvantage – dosing schedule (should be dissolved in mouth 5 times per day)

Answer 20

Clotrimazole (Mycelex)

Mycelex Oral Troches
Disp: fifty (50) Sig: dissolve i slowly PO 5x/day for 10 days

Question 21

Developed during the 1950’s - still used
 Not absorbed systemically - must be in contact with the organism in order to be effective
 Disadvantages: taste (bitter to many), multiple dosing schedule, patient compliance

Answer 21

Nystatin (Mycostatin

for RPD tx - Nystatin Oral Suspension (100,000 u/ml)
Disp: 240 ml Sig: soak denture overnight for 10 days in enough liquid to cover.

**mild bleeach solution used for complete dentures

Question 22

 Triazole antifungal agent
 Readily absorbed systemically- no significant degree of side effects (potential drug interactions)
 Daily dosing is convenient
 Relatively expensive

Answer 22

Fluconazole (Diflucan)

Question 23

Topical Antifungal Agents
Treatment of angular cheilitis or perioral candidiasis:

_- combination of nystatin and triamcinolone

Vytone Cream - combination of iodoquinol and hydrocortisone

Answer 23

Mycolog II Cream - nystatin and triamcinolone

Vytone Cream - iodoquinol and hydrocortisone

Question 24

Endemic to Ohio and Mississippi River valleys
 500,000 new cases in U.S. annually
 Spores in bird or bat droppings

Answer 24

Histoplasmosis

 Histoplasma capsulatum

Question 25

Most cases are asymptomatic – calcified hilar lymph nodes seen coincidentally
 Acute – may have flu-like illness
 Chronic – cavitary pulmonary lesions
 Disseminated – elderly, debilitated, or immunocompromised

Answer 25

Histoplasmosis

Question 26

Oral Lesions
 Usually seen in the disseminated form of the disease
 Affects tongue, palate, or buccal mucosa
 Presents as a chronic variably painful ulcer or granular erythematous plaque
 Clinically may be identical to malignancy

Answer 26

Histoplasmosis

Question 27

Histoplasmosis
 Granulomatous inflammation, with or without necrosis
 1-2 micron yeasts, usually within macrophages
 Best visualized by _

Answer 27

silver stain (GMS) or PAS

Question 28

Dx of histoplasmosis

Answer 28

Identification of characteristic small yeasts in tissue sections

 Culture of the H. capsulatum organism from a suspected lesion

 Serologic testing for antibodies or yeastrelated antigens

Question 29

Histoplasmosis - Treatment

Answer 29

Acute – no treatment is usually necessary

 Chronic or disseminated histoplasmosis – may require amphotericin B

 Ketoconazole or itraconazole for mild cases or as maintenance therapy

Question 30

Histoplasmosis - Prognosis

Answer 30

Acute histoplasmosis in an immunocompetent patient – good

 Chronic histoplasmosis – fair

 Disseminated – poor; mortality rate of 90% if untreated; 7-23% if treated

Question 31

Endemic to desert Southwest U.S.
 100,000 people infected annually in U.S.
 “Valley fever” represents a hypersensitivity reaction

Answer 31

Coccidioidomycosis

 Coccidioides immitis

Question 32

Inhalation of spores
 Flu-like illness in 40% of infected patients
 Dissemination in <1%
 Skin of central face may be affected; oral lesions are rarely described

Answer 32

Coccidioidomycosis

Question 33

Histopathologically shows large (20-60 micron) spherules that contain endospores
 Variable host response, ranging from acute to granulomatous inflammation
 Diagnosis can be made by culture or biopsy

Answer 33

Coccidioidomycosis

Question 34

Coccidioidomycosis tx?

Answer 34

Amphotericin B for disseminated cases

 Fluconazole or itraconazole for milder cases

 May be more aggressive in persons of color

 Generally good prognosis if patient is not immunocompromised

Question 35

Organism lives in pigeon droppings
 Transmitted by air-borne spores
 Affects immunosuppressed patients almost exclusively

Answer 35

Cryptococcosis

 Cryptococcus neoformans

Question 36

Flu-like symptoms with initial pulmonary infection
 Disseminates to meninges, resulting in headache, vomiting, neck stiffness
 Cutaneous lesions may develop in 10-20%
 Oral lesions are rare

Answer 36

Cryptococcosis

Question 37

Histopathologically, 4-6 micron yeasts with a clear halo (representing a mucopolysaccharide capsule)

Organisms may be visualized with mucicarmine, PAS, or silver stain (GMS)

Diagnosis based on culture or identification of organisms in tissue sections

Answer 37

Cryptococcosis

Question 38

Cryptococcosis tx?

Answer 38

Severe cases treated with amphotericin B and flucytosine

 Fluconazole for less severe cases and for maintenance

 Poor prognosis because most patients are immunocompromised

Question 39

 Also known as Mucormycosis
 Several genera of molds, including Mucor, Rhizopus, and Absidia
 Affects severe diabetic or immunocompromised patient
 Rhinocerebral form in oral region

Answer 39

Zygomycosis

Question 40

Nasal obstruction, bloody nasal discharge
 Facial pain, swelling, palatal perforation
 Black, necrotic lesions
 With progression superiorly, visual disturbances and blindness result
 Seizures and death occur with intracranial invasion

Answer 40

Zygomycosis

Question 41

Diagnosis is usually based on histopathologic findings because culture is too slow
 Large, branching, nonseptate hyphae with extensive tissue necrosis
 Hyphae are often seen plugging small blood vessels

Answer 41

Zygomycosis

Question 42

Zygomycosis tx? px?

Answer 42

Radical surgical debridement
 IV amphotericin B
 If patient is diabetic, control of diabetes is important
 Poor prognosis

Question 43

Common; second in frequency to Candidiasis
 Several species
 Spectrum of disease that includes allergy, localized infection or invasive aspergillosis
 Spores in soil, water, decaying organic debris
 May be “nosocomial” infection

Answer 43

Aspergillosis

Question 44

Features vary, depending on immune status and extent of tissue invasion
 Allergy- Allergic fungal sinusitis (may trigger asthma)
 maxillary sinus fungus ball
 Tissue damage - locally invasive
 Immunocompromised patient - disseminated

Answer 44

Aspergillosis

“Aspergilloma” – max sinus fungal ball

Question 45

Biopsy shows branching septate hyphae
 Occlusion of small blood vessels by hyphae
 Granulomatous inflammation if the host is not immune compromised
 Little inflammation if immunocompromised
 Culture can be done, but may be too slow

Answer 45

Aspergillosis

Question 46

Treatment and Prognosis Aspergillosis

invasive vs non-invasive

Answer 46

Non-invasive disease:  debridement

 Invasive disease:  Voriconazole or itraconazole, with or without debridement

 Good prognosis if normal immune status

 Poor prognosis if patient is immunocompromised

Question 47

Was approved for topical use in the US, but tastes bitter, and is no longer available

 IV form is used to treat life-threatening systemic fungal infections

 Nephrotoxicity is significant with standard amphotericin, but newer (expensive) liposomal preparations are relatively non-toxic

Answer 47

Amphotericin B (Fungizone)

Question 48

First oral antifungal agent that could be absorbed systemically- imidazole

 Requires acidic stomach environment
 Single daily dose is convenient
 Problems with drug interactions and idiosyncratic hepatotoxicity (1 in 12,000)

Answer 48

Ketoconazole (Nizoral

Question 49

 Approved for treating histoplasmosis
 Well-absorbed; daily dosing
 Minimal side effects
 Quite expensive

Answer 49

Itraconazole (Sporanox)

Question 50

Triazole compound; IV or oral
 Approved for treating Candida, Aspergillus and several other species
 Side effects include photosensitivity++
 1st line therapy - invasive aspergillosis
 Quite expensive ($460)

Answer 50

Voriconazole