candida

Question 1

give an example of opportunistic fungal infections/genus

Answer 1

Candida
Aspergillus
Cryptococcus
Pneumocystis

Question 2

give an example of cutaneous fungal infections/species

Answer 2

Malassezia (dandruff)
Trichophyton (athlete’s foot)
Microsporum (tinea capitis)

Question 3

how many candida species are pathogenic to humans?

Answer 3

15

Question 4

what is the danger of C. krusei and C. auris?

Answer 4

they’re weak but antifungal resistant

Question 5

give two antifungal resistant Candida species

Answer 5

C. krusei
C. auris

Question 6

what are the main stages of Candida infection

Answer 6

1 colonisation
2 superficial infection
3 deep-seated infection (if immunocompromised)
4 disseminated infection

Question 7

what occurs in the colonisation stage of candida infection?

Answer 7

epithelial adhesion - adhesins, hyphae
nutrient acquisition - hydrolytic enzymes

Question 8

what occurs in the superficial infection stage of candida infection? (3)

Answer 8

penetration - hyphae
damage - toxins and inflammation
host protein degradation - enzymes

Question 9

what occurs in the deep-seated infection stage of candida infection? (2)

Answer 9

further penetration, damage and protein degradation
evasion of host defences

Question 10

what occurs in the disseminated infection stage of candida infection? (2)

Answer 10

endothelial adhesion
tissue penetration

Question 11

how do epithelial cells react to candida infection and what effects does this have? (3)

Answer 11

pro-inflammatory cytokines released to attract WBCs
- direct fungal killing
- barrier repair
- antimicrobial peptides released

Question 12

natural predisposing factors to candida infection (6)

Answer 12

• other infections
• disrupted flora
• cancer, compromised immunity
• pregnancy
• diabetes
• infancy or old age

Question 13

diet predisposing factors to candida infection (2)

Answer 13

• carbohydrate-rich
• haematinic deficiency

Question 14

mechanical/chemical predisposing factors to candida infection (3)

Answer 14

• burns, wounds
• denture wear
• tobacco use

Question 15

iatrogenic predisposing factors to candida infection (2)

Answer 15

• antibiotics
• steroids and immunosuppressive drugs, chemotherapy, transplants

Question 16

other predisposing factors/conditions to candida infection (3)

Answer 16

• HIV/AIDS
• thymic aplasia
• xerostomia

Question 17

list the types of candida infection affecting the oral cavity (7)

Answer 17

• acute pseudomembraneous
• acute atrophic
• erythematous
• chronic mucocutaneous
• angular cheilitis
• chronic hyperplastic
• chronic atrophic

Question 18

describe acute pseudomembraneous candidiasis (presentation, alternative name) (3)

Answer 18

• removable white patches (dead cells, fungae)
• tongue, BM, palate
• AKA thrush

Question 19

what test would you do if you suspected acute pseudomembraneous candidiasis?

Answer 19

smear or saliva test

Question 20

normal sites for acute pseudomembraneous candidiasis (3)

Answer 20

tongue
BM
palate

Question 21

describe acute atrophic candidiasis (AKA, presentation, common association)

Answer 21

• AKA antibiotic sore mouth or acute erythematous candidiasis
• localised or generalised erythema
• bright red, sore tongue
• associated with prolonged broad spectrum antibiotic use

Question 22

common cause of acute atrophic candidiasis

Answer 22

prolonged broad spectrum antibiotic use (antibiotic sore mouth)

Question 23

describe erythematous candidiasis (types, presentation)

Answer 23

• painful localised erythema usually on tongue
• acute = acute atrophic candidiasis/antibiotic sore mouth
• chronic = HIV-associated with kissing lesion on palate
• median rhomboid glossitis form

Question 24

common sites for erythematous candidiasis (2)

Answer 24

tongue
palate if HIV-associated

Question 25

what condition is chronic erythematous candidiasis commonly associated with?

Answer 25

HIV (kissing lesion on palate)

Question 26

describe median rhomboid glossitis (2)

Answer 26

- form of erythematous candidiasis - area of atrophy/erythema on posterior midline of tongue

Question 27

describe chronic mucocutaneous candidiasis (cause, presentation)

Answer 27

- often secondary to immunodeficiency or endocrine disorders - red flat rash of skin folds - scalp, nails affected - non-invasive infection but resistant to topical treatment

Question 28

what is angular cheilitis?

Answer 28

painful cracking at corners of mouth, usually bilateral

Question 29

common causes of angular cheilitis (2)

Answer 29

- overclosure of mouth (saliva) - nutritional deficiency (vit B2)

Question 30

describe chronic hyperplastic candidiasis (presentation, demographic)

Answer 30

- thickened irregular-surfaced white patch that cannot be rubbed off - often bilateral on commissural region of BM, lateral tongue border or palate - often older males, smokers

Question 31

chronic hyperplastic candidiasis common demographic

Answer 31

older males smokers

Question 32

common sites for chronic hyperplastic candidiasis

Answer 32

- bilateral commissural areas of BM - lateral borders of tongue - palate

Question 33

histology of chronic hyperplastic candidiasis (4)

Answer 33

- test-tube rete processes - plasma cells in lamina propria - inflammation in stratum corneum - PAS stain for hyphae

Question 34

what histological stain is used for fungal hyphae?

Answer 34

PAS stain (periodic acid-Schiff)

Question 35

describe chronic atrophic candidiasis (AKA, presentation, cause)

Answer 35

- AKA denture-related stomatitis - redness over denture-bearing mucosa, esp palate - due to poor denture hygiene +/or dry mouth

Question 36

list types of antifungals and their mechanism (4)

Answer 36

1 ergosterol biosynthesis inhibitors - (tri)azoles (eg miconazole) - allylamines (eg terbinafine) - morpholines 2 beta-glucan synthesis inhibitors - echinocandins (eg caspofungin) 3 nucleic acid biosynthesis - pyrimidine analogues 4 pore forming - polyenes (eg amphotericin B, nystatin)

Question 37

what are the three main steps in candidiasis management?

Answer 37

1 diagnosis 2 remove/reduce predisposing factors 3 antifungal medication

Question 38

management of oral-only candidiasis (3)

Answer 38

topicals: - nystatin 3-4x/day (lozenge, pastille, suspension) - miconazole gel 3-4x/day for 2/52 on lips/tongue/denture - soak denture overnight in NaOCl 5000ppm or CHX 0.1% if non-resolving then use systemics

Question 39

management of severe oral +/or body-wide candidiasis (4)

Answer 39

systemic antifungals: - fluconazole 50-100mg OD 10-14 days - itraconazole 100-200mg OD - +/- prophylaxis as 1 week per month medication +/or regular CHX MW - echinocandins if azole-resistant

Question 40

what drug interactions are important to consider with antifungals? (2)

Answer 40

- DOACs/warfarin - especially with azoles - stop statins for use with fluconazole due to rhabdomyolysis)