candida Flashcards
give an example of opportunistic fungal infections/genus
Candida
Aspergillus
Cryptococcus
Pneumocystis
give an example of cutaneous fungal infections/species
Malassezia (dandruff)
Trichophyton (athlete’s foot)
Microsporum (tinea capitis)
how many candida species are pathogenic to humans?
15
what is the danger of C. krusei and C. auris?
they’re weak but antifungal resistant
give two antifungal resistant Candida species
C. krusei
C. auris
what are the main stages of Candida infection
1 colonisation
2 superficial infection
3 deep-seated infection (if immunocompromised)
4 disseminated infection
what occurs in the colonisation stage of candida infection?
epithelial adhesion - adhesins, hyphae
nutrient acquisition - hydrolytic enzymes
what occurs in the superficial infection stage of candida infection? (3)
penetration - hyphae
damage - toxins and inflammation
host protein degradation - enzymes
what occurs in the deep-seated infection stage of candida infection? (2)
further penetration, damage and protein degradation
evasion of host defences
what occurs in the disseminated infection stage of candida infection? (2)
endothelial adhesion
tissue penetration
how do epithelial cells react to candida infection and what effects does this have? (3)
pro-inflammatory cytokines released to attract WBCs
- direct fungal killing
- barrier repair
- antimicrobial peptides released
natural predisposing factors to candida infection (6)
- other infections
- disrupted flora
- cancer, compromised immunity
- pregnancy
- diabetes
- infancy or old age
diet predisposing factors to candida infection (2)
- carbohydrate-rich
- haematinic deficiency
mechanical/chemical predisposing factors to candida infection (3)
- burns, wounds
- denture wear
- tobacco use
iatrogenic predisposing factors to candida infection (2)
- antibiotics
- steroids and immunosuppressive drugs, chemotherapy, transplants
other predisposing factors/conditions to candida infection (3)
- HIV/AIDS
- thymic aplasia
- xerostomia
list the types of candida infection affecting the oral cavity (7)
- acute pseudomembraneous
- acute atrophic
- erythematous
- chronic mucocutaneous
- angular cheilitis
- chronic hyperplastic
- chronic atrophic
describe acute pseudomembraneous candidiasis (presentation, alternative name) (3)
- removable white patches (dead cells, fungae)
- tongue, BM, palate
- AKA thrush
what test would you do if you suspected acute pseudomembraneous candidiasis?
smear or saliva test
normal sites for acute pseudomembraneous candidiasis (3)
tongue
BM
palate
describe acute atrophic candidiasis (AKA, presentation, common association)
- AKA antibiotic sore mouth or acute erythematous candidiasis
- localised or generalised erythema
- bright red, sore tongue
- associated with prolonged broad spectrum antibiotic use
common cause of acute atrophic candidiasis
prolonged broad spectrum antibiotic use (antibiotic sore mouth)
describe erythematous candidiasis (types, presentation)
- 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
common sites for erythematous candidiasis (2)
tongue
palate if HIV-associated
what condition is chronic erythematous candidiasis commonly associated with?
HIV (kissing lesion on palate)
describe median rhomboid glossitis (2)
- form of erythematous candidiasis
- area of atrophy/erythema on posterior midline of tongue
describe chronic mucocutaneous candidiasis (cause, presentation)
- often secondary to immunodeficiency or endocrine disorders
- red flat rash of skin folds
- scalp, nails affected
- non-invasive infection but resistant to topical treatment
what is angular cheilitis?
painful cracking at corners of mouth, usually bilateral
common causes of angular cheilitis (2)
- overclosure of mouth (saliva)
- nutritional deficiency (vit B2)
describe chronic hyperplastic candidiasis (presentation, demographic)
- 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
chronic hyperplastic candidiasis common demographic
older males
smokers
common sites for chronic hyperplastic candidiasis
- bilateral commissural areas of BM
- lateral borders of tongue
- palate
histology of chronic hyperplastic candidiasis (4)
- test-tube rete processes
- plasma cells in lamina propria
- inflammation in stratum corneum
- PAS stain for hyphae
what histological stain is used for fungal hyphae?
PAS stain (periodic acid-Schiff)
describe chronic atrophic candidiasis (AKA, presentation, cause)
- AKA denture-related stomatitis
- redness over denture-bearing mucosa, esp palate
- due to poor denture hygiene +/or dry mouth
list types of antifungals and their mechanism (4)
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)
what are the three main steps in candidiasis management?
1 diagnosis
2 remove/reduce predisposing factors
3 antifungal medication
management of oral-only candidiasis (3)
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
management of severe oral +/or body-wide candidiasis (4)
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
what drug interactions are important to consider with antifungals? (2)
- DOACs/warfarin - especially with azoles
- stop statins for use with fluconazole due to rhabdomyolysis)
