Candida Flashcards
Is Candida always harmful?
No
Candida spp are normally harmless commensals but under certain conditions may switch to pathogenic form & cause disease aka an OPPORTUNISTIC PATHOGEN
Which species of Candida is commonly found in the mouth?
Candida Albicans
Name 3 other pathogenic species of Candida?
- C. glabrata
- C.krusei
- C. Tropicalis
State candida morphology:
Pleomorphic (‘variation of size & shape of cells/nuclei’)
How does commensal Candida become pathogenic?
Initially OVOID YEAST CELLS which undergo morphological changes under certain environmental conditions to FILAMENTOUS FORMS known as hyphae and pseudohyphae
- Hyphal cells allow invasions into submucosal tissue, colinisation + macrophage evasion
Where in the mouth is the primary resevoir for Candida?
dorsum of tongue in-between the filiform papilla
What are the risks factors for Candidal growth?
1.Pregnancy
2.Smoking
3.Poorly controlled diabetes
4. Poorly controlled HIV
5. Denture wearers
State 9 GENERAL FACTORS that encourage candida growth & colonisation?
- Broad spectrum antibiotics (e.g. penicillin. Antibiotics alter the commensal oral microflora)
- Corticosteriods (increase glucose levels by decreasing insulin sensitivity)
- Cytotoxic drugs (used for chemotherapy)
- Xerogenic drugs (reduce salivary flushing + antifungal salivary components like lysozyme or sIgA)
- Xerostomia
- Nutritional deficiencies (iron, folate, B12, VitC and possibly vitA –> reduced host defences + mucosal integrity paired with/ carb rich diets)
- Poorly controlled diabetes (poor glycemic control, increased salivary glucose conc. + xerostomia)
- Immunosuppression (extremes of age + HIV affect CD4 count)
- Haematological factors (blood group O are at increased risk)
State 4 LOCAL FACTORS that encourage candida growth & colonisation?
- Trauma e.g. ill-fitting prostheses
- Tobacco smoking
- Reduced salivary flow
- Carb rich diet (candida thrives on glucose)
IO features of oral candida infection?
Rarely causes local discomfort
Sometimes altered taste & sensation of oral dryness
If oral candida spreads to oesophagus –> dysphagia or chest pain
In immunocompromised pt’s candida infection can spread into bloodstream or upper GI causing sever infection
State the classification of oral candidiasis
- Acute forms:
Pseudomembranous candidosis
Erythematous candidosis - Chronic forms:
Hyperplastic (CHC)
Erythematous denture induced candidiasis (CEC) - Secondary forms:
Angular chelates
Median rhomboid glossitis
Chronic mucocutaneous candidosis (CMC)
State all facts about Pseudomembranous candidosis ‘aka thrush’ (acute form of OC):
DETACHABLE confluent creamy-white or yellowish patches of candida deposits (‘milk curds’) on oral mucosal surfaces (tongue + palate)
Consisting of:
desquamated epithelial cells
necrotic material
fibrin + fungal hyphae
- Wiped off relatively easily revealing a erythematous base (that occ bleeds)
- Predisposing factors:
IMMUNOCOMPRIMISED
Age
Poorly controlled diabetes
Malignancies including leukaemia
HIV (risk of developing oesophageal candidosis)
Immunosuppressant drugs
Angular chellitis
Common sites: dorsum of tongue between filiform papillae and on hard palate.
IO signs: atrophic tongue (smooth + depapilated due to absence of filiform papilla). Red erythematous base when rubbed off hard palate
Management of thrush:
- OHI (gentle tongue brushing/ scraping)
- Investigate + treat systemic issues (immunosuppression, anaemia Fe, Vit B12, Folate), diabetes, HYPOthyroidism, smoking cessation)
- Live active yoghurt
- Topical agents: CHX m/w (diluted), nystatin suspension, miconazole oral gel
State all facts about Erythematous candidosis (acute form of OC):
Characterised by +/- painful erythematous patches
- Commonly occurring sites: dorsum of tongue + palate (rarely buccal mucosa)
- Mainly assoc. w chronic use of broad spectrum antibiotics + corticosteroids
- Also assoc. w/ HIV pts
IO Appearance:
- Depapillation & reddening in the central area of dorsum of the tongue
- in other cases tongue coating & possible
candida overgrowth of dorsum of tongue
Management:
Same as Pseudomonas Candidiasis
State all facts about Chronic hyperplastic candidosis CHC (chronic form of OC):
(Formerly known as candidal leukoplakia)
= Form of chronic hyperkeratosis (thickening) in which candida is identified
- Generally asymptomatic
- Predisposed to: middle-aged male smokers
- Commonly occurring site: the angles of the buccal mucosa towards commissures w bilateral distribution)
- May be assoc. w/ ANGULAR CHELLLITIS
IO Appearance:
white - erythematous raised lesions which DO NOT rub off
May be:
nodular/speckled [more prone to malignant change], or
homogeneous plaque-like
hyperplastic white areas
Key reason to refer: ability of candida to produce nitrosamines, –> risk of malignant epithelial transformation
If left untreated, may transform into SSC (squamous cell carcinoma)
Management:
- Biopsy = ESSENTIAL (~15% risk of malignant transformation)
- Check haematinic levels (iron, folate, vitB12, TFT + glucose levels)
- Smoking cessation
- Diabetes must be well managed
- Systemic oral antifungals:
2-4+ weeks ORAL FLUCONAZOLE (topical antifungals not effective as candida is embedded into tissue)
State all facts about Chronic erythematous candidosis CEC (chronic form of OC):
= aka DENTURE STOMATITIS ~ affecting 65% of denture wearers (historically mistaken for hypersensitivity to acrylic)
= Chronic erythema of mucosa from candida beneath fit surface of acrylic upper denture (or occasionally on
orthodontic appliance)
- Fit of denture excludes saliva from supporting mucosa, allowing commensal Candida to overgrow in a supportive environment; usually asymptomatic
Affecting: upper arch (hard palate); rarely affecting lower arch
Assoc w:
- inadequate oral/denture hygiene
- poorly fitting dentures causing trauma to fit surface
- Angular Chellitis
IO appearance: erythema of palatal mucosa w sharply defined margin i.e. where the denture sits
- If relief area present, may result in underlying spongy, granular changes (newton type 2)
Newton’s classification:
Type 1- Pin-point hyperaemia
Type 2- Diffuse erythema limited to fit surface of denture
Type 3- Nodular appearance of palatal mucosa
Management of denture stomatitis:
- Address denture hygiene (regular cleaning + remove at night)
- Eliminate tissue trauma (tissue conditioners PEMA)
- Miconazole gel applied to fit surface of denture (BUT CAN BE ABSORBED SYSTEMICALLY + INTERACT W/ DRUGS LIKE WARFARIN OR STATINS)
- If, lack of resolution consider systemic issues (blood test) or lack of OHI compliance
State all facts about Angular Cheilitis (secondary form of OC):
aka angular stomatitis
Multifactorial condition (of C. albicans, Staphylococcus aureus & Streptococci)
Description: decreased vertical dimension w/ maceration (softening) of underlying skin assoc w/ pooling of saliva
Who? Elderly edentulous patients w/ denture stomatitis (CEC)
Presentation: Symmetrical erythematous fissuring at angles of mouth/commissures
Aetiology:
1. Lip morphology + reduced vertical dimension
2. Malabsorption disorders (Coeliac, Crohns, orofacial granulomatosis)
3. Reduced haematinic levels (B12, folate, iron)
4. Immunosuppression (HIV)
5. Diabetes
6. Broad spectrum antibiotics
7. Xerostomia e.g. Medication or Sjogrens
Management:
Correct predisposing factors
- Correct reduced vertical dimension (e.g. reorganise denture to increase OVD)
- improve oral + denture hygiene
- address deep fissuring (botox)
- address malabsorption disorder
Tx intraoral candida - topical agents
- Miconazole oral gel on corners of mouth (one off)
- Chronic angular cheilitis -> Trimovate cream to corner of lips (antifungal, antibiotic + steroid)
State all facts about Median Rhomboid Glossitis (secondary form of OC):
= Localised candidal infection w atrophy of filiform papillae
(asymptomatic diamond ‘rhomboid’ shaped smooth area anterior to the circumvallate papillae on tongue)
Assoc w/:
- Smoking
- Use of corticosteroid inhalers (inhaler technique may be poor)
Tx:
- spacer device + rinse after inhaler spray
- smoking cessation
State all facts about Chronic Mucocutaneous Candidosis CMC (secondary form of OC):
= Chronic candidal infection involving skin, nails + mucous membranes
Aetiology: Impaired cellular immunity to Candida
Age of onset: baby - 18 years old-
Assoc w rare congenital conditions, eg Autoimmune polyendocrine
syndrome type 1 [APS-1] = hypothyroidism, primary adrenocortical
insufficiency & chronic mucocutaneous candidosis
CMC in APS-:
-Diagnosis of oral candidosis
Initially presentation: oral thrush w angular cheilitis (that is resistant
to tx)
-Becomes more chronic w atrophy & leukoplakia (painful w acidic &
spicy food)
-Association w OSCC
-Infection needs to be controlled
-Oesophagus may be involved w retrosternal pain & stricture
formation
How do you diagnose oral candidiasis? (general)
Clinically diagnosed
If possible/needed microbial sample can be take:
- to identify + quantify Candida species
- to assess if anti fungal resistant strain present e.g. C.glabrata + C.krusei
Other candidal sampling methods:
whole saliva culture,
concentrated oral rinse
swab + smear slidee
sponge imprint culture
biopsy (invasive; used for CHC)
State the indications for when to use topical vs systemic anti-fungal agents:
Topical = superficial infection (denture wearer, antibiotic px, diabetic)
Systemic= immunosuppressed, CHC
Name 2 types of antifungal agents?
- Polyenes e.g. Nystatin + Amphoterecin
- Azoles e.g. Fluconazole, Miconazole, Ketaconazole
State the mechanism of action + administration of Polyenes?
MOA: disruption of fungal cell membrane (not absorbed by the gut)
A: Topical
State the mechanism of action + administration of Azoles?
MOA: inhabitation of ergosterol synthesis (absorbed by gut)
A: Topical/systemic
What is Px for Nystatin?
Oral suspension 100 000 I units 4 x day for 7-14 days
What is the px for miconazole (topical)?
gel 25mg/ml used 4xday for 14 days after meals
SE: oral irritation, sensitisation, nausea
Does miconazole only treat Candida?
No, it has anti-staphylococcal activity too
What is the px for Fluconazole (systemic)?
50mg once daily for 7-14 days
Contraindicated in pregnancy + breast feeding
SE:
Nausea, vomiting, abdominal distension, diarrhoea & flatulence
Rashes incl erythema multiforme
Hepatitis
Why is Ketaconazole rarely prescribed?
= Hepatotoxic; not used in patients w/ hx of liver disease or alcoholics
What drug interactions do Azoles have?
- Benzodiazepines (-zolam/ -zepam)
- Ca channel blockers (-dipine)
- Immunosuppressive calcineurin inhibitor (eg ciclosporin)
- Statins
- Warfarin
- (Fluconazole contraindicated in pregnancy + breast feeding)
What species of candida are resistant to fluconazole?
- C.Glabrata
- C.Krusei
- C.Dublinesis
(Echinocandins developed to combat resistant strains)
State px for amphotericin?
Lozenges 10mg 4 x times a day 10-15days
(can be used for IV)
SE: mild gastrointestinal disturbances
What is tongue coating and how do you manage it?
= overgrowth of keratin, bacteria, + debris on papillae
Management: reassure pt, fluid intake, + gentle tongue brushing
EXAM Q
A dentist is unable to treat a patient’s Oral candidiasis and refers the patient to you.
a. List FOUR different candidal infections found within the oral cavity and describe the clinical features that distinguish them (4 marks)
- Acute pseudomembranous candidosis (Oral thrush): Confluent creamy-white or yellowish patches on oral mucosal surfaces, which can be wiped to reveal an erythematous occasionally bleeding base. Lesions are usually asymptomatic
- Erythematous candidosis: Characterised by +/- painful erythematous patches, commonly on the dorsum of the tongue and palate (occasionally buccal mucosa)
- Chronic Hyperplastic Candidiasis (CHC): White to erythematous raised lesions which do not rub off usually on the buccal mucosa towards commisures with bilateral distribution. Lesions are generally asymptomatic. If left untreated risk of malignant transformation to OSCC (~ 15% risk). Lesions may be nodular/speckled or homogenous plaque-like
- Denture stomatitis (Chronic Erythematous candidosis): chronic erythema of mucosa beneath fit surface of acrylic denture or orthodontic appliance. Mainly affects upper arch and is asymptomatic. Associated with angular cheilitis.
EXAM Q
b. List FIVE factors which may predispose a patient to a candida infection of the mouth. Give the most likely type of candida lesion associates with each predisposing factor (6 marks)
- Immunocompromised e.g. HIV disease, extremes of age, malignancies - Acute pseudomembranous candidosis (Oral thrush)
- Chronic use of broad spectrum antibiotics - (Acute) Erythematous candidosis
- Smoking - Chronic Hyperplastic Candidiasis (CHC)
- Poor oral/denture hygiene (and poor fitting dentures causing trauma to fit surface) - Denture stomatitis
- Xerostomia - Acute pseudomembranous candidosis
EXAM Q
c. How may the diagnosis of candida be confirmed in the laboratory and which microbiological sampling procedures would you use (5 marks)
Microbial sample e.g. swab: identify and quantify Candida spp present and assess antifungal resistance - diagnosis confirmed by presence of Candidal hyphae, which can be stained using the gram stain and are gram positive.
Biopsy (if CHC): condition premalignant, risk of malignant transformation ~ 15%
Laboratory:
* Check iron/folate/vitamin B12, thyroid function tests (TFTs) and glucose levels - aim to determine cause of infection
Others: whole saliva culture (not suitable in xerostomia), smears or sponge imprint cultures
EXAM Q
d. What are the principles of treatment of candida infection? (5 marks)
- Diagnosis of infection and strain of candida/causative microorganism - some such as C.dublinensis and C.Glabrata are less susceptible to antifungals such as Fluconazole
- Risk/aetiological factor management: xerostomia, (poorly controlled) diabetes, immunosuppression, smoking cessation, chronic use of broad spectrum antibiotics, trauma from ill-fitting dentures or poor oral/denture hygiene, amongst others
- Pharmacological management: Miconazole gel, if contraindicated (due to drug interactions or other reasons) Nystatin, and for severe or recurrent infections consider Fluconazole
- Pain relief: analgesic such as Difflam Spray
- For patients using inhaled corticosteroids - counsell on using a spacer and washing mouth after use
- Monitor and review patient - no signs of improvement consider referral to specialist to check iron/folate/vitamin B12, thyroid function tests and glucose levels
- For CHC biopsy important as this is a premalignant condition with a risk of malignant transformation ~ 15%
EXAM Q
Denture stomatitis:
a. What is denture stomatitis?
- Chronic erythema of mucosa beneath fit surface of acrylic upper denture or occasionally orthodontic appliance
- Clinically marked erythema of mucosa with sharply defined margins corresponding to the periphery of the appliance
- Usually asymptomatic, rare affects lower arch and may be associated with angular cheilitis
EXAM Q
b. What causes denture stomatitis and how is it classified?
- Primary causes: inadequate oral/denture hygiene and poorly fitting dentures causing trauma to fit surface
- Other causes: general risk factors for candidial infection e.g. xerostomia, (poorly controlled) diabetes mellitus, immunosuppression, broad spectrum antibiotics, reduced haematinic levels, amongst others
Classified using Newton’s classification of denture stomatitis:
* Type 1: Pin-point hyperaemia
* Type 2: Diffuse erythema limited to fit surface of denture
* Type 3: Nodular appearance of palatal mucosa
EXAM Q
c. How do you manage denture stomatitis?
- Improve oral hygiene
- Address denture hygiene - regular cleaning of denture and leave denture in sodium hypochlorite or 2% chlorhexidine overnight
- Advice on denture usage - avoid prolonged/night-time wearing
- Eliminate tissue trauma - tissue conditioners
- Miconazole gel applied to fit surface of denture: dose = gel 25 mg/mL used 4x day for 14 days after meals
o If miconazole contraindicated - Nystatin oral suspension 100,000 units 4x day for 7-14 days
o If severe - Fluconazole, 50 mg once a day for 7-14 days
o Care with Fluconazole and Miconazole CYP enzyme inhibitors therefore potentiating the anticoagulant effect of Warfarin and toxicity associated with Statins or other drugs metabolismed by CYP enzymes
EXAM Q
d. If denture stomatitis does not improve, then what should you do?
- Lack of resolution consider systemic issues or lack of compliance
- Refer for special investigations if doesn’t heal within few weeks
EXAM Q
e. What is the cause of angular stomatitis?
- Correct predisposing factors: improve oral and denture hygiene, treat any underlying causes
- Correct vertical dimension
- Address deep fissuring
- Treat intraoral candida - topical agents. Use Miconazole (if not contraindicated due to drug interactions) oral gel applied to * corners of mouth
- In correct angular cheilitis - Trimovate cream to corner of lips
EXAM Q
g. On a swab/smear what would you expect to see? (candida swab)
Candidial growth:
* Desquamated epithelial cells
* Necrotic material
* Fibrin
* Fungal hyphae
Presence of Staphylococcus aureus (+/- B-haemolytic Streptococci)
EXAM Q
h. What THREE situations would you refer angular stomatitis for special investigations?
- Lack of resolution following antifungal treatment and removal of predisposing factors to identify any underlying conditions which may be causing the angular stomatitis e.g. anaemia, OFG, Crohns, HIV etc.
- If suspected allergic contact dermatitis – refer for patch testing
- If you suspect actinic chelitis, you must refer the patient as these lesions are at increased risk of transformation into OSCC
- Recurrent episodes of angular stomatitis which may indicate underlying immunosuppression – refer for special investigations even if healing
EXAM Q
Candida:
A 30 year old lady attends your practice complaining of white creamy patches on her palate and throat
a. What is your “working” diagnosis? (1 mark)
Acute pseudomembraneous candidosis
EXAM Q
b. Which group are predisposed to chronic hyperplastic candidiasis?
- Smokers
- Immunocompromised e.g. HIV/AIDS
- (Poorly controlled) diabetes
- Xerostomia
- Medications: corticosteroids, (broad spectrum) antibiotics, cytotoxic agents
- Nutritional deficiencies or carbohydrate rich diet
- Haematinic deficiency (iron, B12, folate)
- Trauma e.g. ill-fitting prostheses (denture)
