Fungal Infections Flashcards
General predisposing factors to opportunistic infection?
1) Broad-spectrum Antibiotics
2) Corticosteroids (Immunomodulators)
3) Cytotoxics
4) Poorly Controlled Diabetes Mellitus
5) Xerostomia
6) Nutritional Deficiencies
7) Immunosuppression (e.g. extremes of age or HIV)
8) Haematological
Local predisposing factors to opportunistic infection?
1) Trauma (e.g. ill-fitting prostheses)
2) Tobacco Smoking
3) Reduced Salivary Flow
4) Carbohydrate-rich Diet
-> Increased Candida adherence to epithelial cells
2 acute forms of fungal infection?
Pseudomembranous candidosis
Erythematous candidosis
3 chronic forms of candidosis?
Hyperplastic
Erythematous (denture stomatitis)
Chronic secondary forms of fungal infection?
Median rhomboid glossitis
Angular cheilitis
Chronic mucocutaneous candidosis
Clinical presentation of thrush?
Detachable confluent-white or yellow patches (milk curds) on oral mucosa (often palate)
Wiped away to leave erythematous, bleeding base
Often asymptomatic
Histology of white plaques?
Desquamated epithelial cells
Necrotic material
Fibrin
Fungal hyphae
Risk factors of thrush?
Immunocompromised pt (extremes of age, poorly controlled diabetes, malignancy, HIV, leukaemia or immunosuppressant drug users)
Thrush is often associated with…
Angular cheilitis
Oesophageal candidosis (particularly in HIV pts) -> odynophagia, dysphagia & chest pain
Management of thrush?
Improve OH
Identify & treat systemic predisposing factor (e.g. immunosuppression, deficiencies, diabetes etc)
Live active yoghurt (encourages return to normal microflora)
Topical agents:
- CHX m/w (antibacterial & antifungal)
- Nystatin suspension
- Miconazole oral gel (avoid with warfarin)
Clinical presentation of acute erythematous candidosis?
Painful erythematous patches
Commonly on dorsum of tongue & palate
What is acute erythematous candidosis associated with?
LT broad-spectrum antibiotic use (antibiotic sore mouth)
LT corticosteroid use
HIV
Clinical presentation of chronic hyperplastic candidosis?
White-erythematous raised lesions which do not rub off
Usually asymptomatic & found bilaterally on buccal mucosa (towards commissures)
Nodular/speckled = more prone to malignant change OR homogenous plaque-like
What is CHC associated with?
Middle-aged male smokers
What is the risk associated with CHC?
Malignant transformation to OSCC
If left untreated, 5-10% show dysplasia & may transform to OSCC
Angular cheilitis
How to manage CHC?
Biopsy (as it is a premalignant lesion)
FBC (vitamin, iron, folate, glucose levels) & thyroid tests
Remove predisposing factors (e.g. smoking)
Topical antifungals not effective => 2-4+ weeks oral (systemic) fluconazole
What is denture stomatitis (chronic erythematous candidosis)?
Chronic erythema of mucosa below fit surface of acrylic upper denture or ortho appliance
Aetiology of denture stomatitis?
Denture or appliance fit => saliva excluded from supporting mucosa & commensal candida overgrowth occurs
Clinical presentation of denture stomatitis?
Marked erythema of palatal mucosa with margins corresponding to appliance
‘Relief areas’ of denture may have underlying spongy granular change
Usually asymptomatic or angular cheiiltis present
What is denture stomatitis associated with?
Poor OH
Poor denture design (non-hygienic design OR poorly fitting denture => trauma)
Newton’s classification of denture stomatitis
Type
1 = Pin-point hyperaemia
2 = Diffuse erythema limited to fit surface of denture
3 = Nodular appearance of palatal mucosa
Management of denture stomatitis?
Improve denture cleaning:
- Regular cleaning instruction +/- antiseptic soak (e.g. CHX)
- Eliminate tissue trauma (tissue conditioners)
- Improved design (more hygienic or less traumatic)
Antifungal - miconazole gel (applied to denture fit surface) except warfarin & statin pt
Review - if lack of resolution consider systemic issue or lack of compliance
Clinical presentation of median rhomboid glossitis?
Asymptomatic diamond-shaped smooth erythematous area at junction between anterior 2/3rd & posterior 1/3rd of tongue (anterior to circumvallate papillae)
Localised candida infection leading to filiform papillae atrophy
‘Kissing lesion’ = similar patch on palate
What is associated with median rhomboid glossitis?
Smoking & corticosteroid use (asthmatics)
Aetiology of angular cheilitis?
Multi-factorial infection with C. albicans, S. aureus & B-haemolytic streptococci
Clinical presentation of angular cheilitis?
Symmetrical erythematous fissuring at commissures +/- yellow crusting
What is the main demographic associated with angular cheilitis?
Elderly edentulous pts with denture stomatitis
Decreased vertical dimension => maceration of underlying skin by saliva
Risk factors of angular cheilitis?
Lip morphology
Malnutrition
- Reduced haematinic levels (iron, B12, folate)
- Malabsorption disorders (e.g. Crohns, OFG)
Immunosuppression (e.g. HIV)
Diabetes
Broad-spectrum antibiotics
Xerostomia (e.g. age, medication related or Sjogren’s)
Management of angular cheilitis?
Correct predisposing factor (e.g. increase denture OVD)
Treat candida infection
- I/O = topical antifungal
- E/O = miconzaole gel applied to corners of mouth
How to treat chronic angular cheilitis?
Trimovate cream application
(Triad: antifungal, antibacterial & steroidal)
Why take a microbial sample?
Identify candida species & their antifungal resistance
Identify candida quantity
Sampling methods & advantages & disadvantages?
Whole saliva culture
+ Gives fungal load
- Not suitable in xerostomia
Concentrated oral rinse
+ Gives fungal load
Swab
+ Site specific
- Not quantitative
Smear
+ No lengthy culture required
- Candida species not identified
Sponge imprint culture
+ Gives fungal load
+ Site specific
Biopsy
+ Indicated for CHC
- MOS procedure
How to polyenes work & give example?
Fungicidal - generate pores in cell membrane => leakage
Not absorbed by gut
e.g. Nystatin
How do azoles work & give example?
Fungostatic - interfere with ergosterol fungal cell membrane synthesis
e.g. Miconazole, fluconazole
When do you give topical antifungal agents?
Superficial infections
e.g. Denture wear, antibiotic drug use or diabetics
How is miconazole gel applied & what risks?
To affected area or fit surface of denture (can be left in)
GIT absorption => serious interactions with warfarin & statins
When do you use systemic antifungals?
Immunosuppressed
Candidal leukoplakia
