Candidiasis Flashcards
Candida Species
> Most common opportunistic fungal pathogen
> Causes mucosal infections, which are generally NON-INVASIVE are caused primarily by Candida albicans
5 most common Candida Species causing invasive disease
C. albicans C. glabrata C. tropicalis C. parapsilosis C. krusei
Commensalism vs. Disease State
more than 50% of humans carry candida w/o harmful effects, but becomes an “infection” when environment changes and encourages growth
Usually defect in cell-mediated immune response
Ranges from mild superficial mucosal infection to fatal disseminated disease
Causes for Candida Infection
- A disrupted balance of the normal mucosal flora
- Impaired barrier functions
- Immunosuppression such as broad spectrum antibiotics, leukemia, HIV, cancer chemotherapy, diabetes, xerostomia
Pathogenesis of Candidiasis
- Fungal burden is increased and hyphae form
- Immune cells are recruited by cytokines, chemokines
- Neutrophils are recruited and kill fungus
- Dendritic cells present antigen to T-cells
- T-cells also decrease fungal burden (IL-22, IL-17)
- Innate and acquired clear fungus to levels below threshold
How does Candida overcome host defenses?
- Dimorphism (two growth phases due to environmental changes; hyphal form associated with invasion and goes into the parakeratin layer)
- Phenotypic switching (Can change into different shapes which prevent identification by neutrophils)
- Adhesins/Invasins (Help the fungal organize attach to epithelial cells; invasin = endocytosis (inside cells))
- Molecular mimicry of mammalian integrins (has integrin-like molecules which allow for adhesion to cells)
- Secretion of hydrolytic enzymes (Break down epithelial cells)
- Phospholipase B contributes to degradation of host tissues
Candida Albicans Cell Wall
- Protects against environmental stress
- Antigenic determinants
- Forms contact with host cells, plasma and body fluids
- Mediates adherence of the pathogen to the host surface
- Allows establishment of cross-talk with host
Types of Candidiasis Infection
> Superficial and localized-more common (mild disease and often what we see in the oral cavity)
- Intertrigo - Paronychia/Onychomycosis - Diaper Rash - Vulvovaginitis - Esophageal candidiasis - Oral Candidiasis (Candidosis)
> Invasive, disseminated and deep infection-rare (moderate-severe)
- Affects blood (candidemia-hospitalized), heart, brain,
eyes, bones
Invasive Candidiasis infects…
bloodstream (candidemia) heart (candida endocarditis) periosteum (peritonitis) bone (osteomyelitis) joints (candida arthritis) eyes (endophthalmitis)
Candidal Sepsis
- Very rare
- Life-threatening event in individual with severely deficient cell-mediated immunity
- C. albicans most common species
- Most commonly involves urinary tract infection (women/men 4:1)
Pseudomembranous (thrush)
Appearance/Symptoms:
-Creamy-white plaques, removable/wipeable; burning sensation, foul taste
- Underlying mucosa is erythematous
- Asymptomatic usually
Common Sites:
- buccal mucosa
- tongue
- palate
Who gets it?
- HIV, broad-spectrum antibiotics, leukemia, infants
Erythematous Candidiasis
Appearance/Symptoms:
- Red macules or patches
- burning sensation
Subtypes:
- atrophic candidiasis
- median rhomboid glossitis
- denture stomatitis
Common Sites:
- posterior hard palate
- buccal mucosa
- dorsal tongue
Central papillary atrophy
median rhomboid glossitis
Appearance/Symptoms:
- Red, atrophic mucosal areas
- Asymptomatic
- well demarcated erythematous zone
- Loss of papillae
- “Kissing” palatal lesion (when the tongue touches the palate, it transfers the fungal infection over)
Common Sites:
- Midline posterior dorsal tongue
Chronic multifocal
Appearance/Symptoms:
-Red areas, often with removable white plaques; burning sensation; asymptomatic
Common Sites:
- posterior palate
- posterior dorsal tongue
- angles of the mouth
Angular chelitis
Appearance and Symptoms:
Red, fissured lesions; irritated, raw feeling
Seen with loss of vertical dimension/pooling of saliva
May be mixed bacterial/fungal infection
Common Sites:
-angles of the mouth
Denture stomatitis (chronic atrophic candidiasis, denture sore mouth)
Appearance and Symptoms:
Red, asymptomatic
petechiae may be noted
inflammatory papillary hyperplasia is associated with condition (not CAUSED but strongly associated)
Common Sites:
-confined to palatal denture bearing mucosa in maxilla
Hyperplastic (candidal leukoplakia)
Appearance and Symptoms:
- white plaques that are not removable; asymptomatic
-increased frequency of epithelial dysplasia (theory of candida inf. over pre-existing leukoplakia?)
Common Sites:
-anterior buccal mucosa
Mucocutaneous
Appearance and Symptoms:
-white plaques, some of which may be removable; red areas
Common Sites:
- tongue
- buccal mucosa
- palate
Endocrine-candidiasis syndromes
Appearance and Symptoms:
-white plaques, most of which are removable
Common Sites:
- tongue
- buccal mucosa
- palate
Predisposing factors to Candida
Local
- denture wearing
- smoking
- atopic constitution
- inhalation steroids
- topic steroids
- hyperkeratosis
- imbalance of the oral microflora
- quality of saliva
General
- immunosuppressive diseases
- impaired health status
- immunosuppressive drugs
- chemotherapy
- endocrine disorders
- hematinic deficiencies
Atrophic Candidiasis
Erythematous areas on any mucosal surface
“Bald tongue”
Typically painful
Common with inhalation steroids; if they rinse after use though, it usually subsides
Chronic Mucocutaneous Candidiasis
Group of rare disorders with immunologic pathogenesis
Clinical: Severe infection of mucosal surfaces, nails, and skin
Oral lesions-thick white plaques that do not rub off but may see other forms
May be associated with endocrine abnormalities (APECED)
Tx. Systemic antifungals
Increased risk for squamous cell carcinoma?
Ex. Tongue has formed a white and thickened plaque as well as skin, nails, and feet which cannot rub off
APECED
Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy Syndrome
Diagnosis of Oral Candidiasis
-Clinical signs
-Therapeutic diagnosis
-Cytologic smear
Periodic Acid Schiff Stain
(PAS stain)
KOH float (Immediate result but you can’t keep the
slide as a record and cannot evaluate epithelial cells
using Potassium hydroxide)
- Biopsy (esp. hyperplastic candidiasis)
- Culture
Biopsy Results
Hyperplastic epithelium so it clinically appears WHITE
FUNGAL HYPHAE ALWAYS IN THE SURFACE PARAKERATIN LAYER (nuclei present in the keratin layer)
Antifungal Drugs
- Polyene-Nystatin, Amphotericin B
- Imidazole-Clotrimazole, Ketoconazole (GI absorption)
- Triazole-Fluconazole, Itraconazole, Posaconazole, Echinocandins
Treatment of Mild Disease
Clotrimazole troches, 10 mg 5 times daily OR miconazole mucoadhesive buccal 50 mg tablet applied to the mucosal surface once daily for 7–14 days
Alt: Nystatin suspension (100 000 U/mL) 4–6 mL swished for >1min then swallow 4 times daily
Treatment of Moderate to Severe Disease
Oral fluconazole, 100–200mg daily for 7–14 days is recommended
Pharmacokinetics: Fluconazole inhibits CYP2C9, CYP2C19, and CYP3A4 isoenzymes
Check for interactions with medications that are metabolized through this mechanism
For some medications fluconazole may be contraindicated
Alt: do exist but we would not prescribe reference slide if you care
Fluconazole Adverse Reactions
Central nervous system: Headache/ dizziness
Dermatologic: Skin rash
Gastrointestinal: Nausea, abdominal pain, vomiting, diarrhea, dysgeusia, dyspepsia
Hepatic: Hepatitis, increased serum alkaline phosphatase, increased serum ALT, increased serum AST, jaundice
Chronic Suppressive Therapy
Usually unnecessary in immunocompetent patients
Advise antiviral therapy to prevent opportunistic infections to begin with
Fluconazole, 100 mg 3 times weekly, is recommended
Denture Stomatitis Treatment
The scope of treatment is broad and included strategies that targeted biofilm formation on the prosthesis as well as targeted approaches focused on treatment of a fungal infection of tissues.
disinfection methods could also considered as an adjunct or alternative to antifungal medications in the treatment of denture stomatitis. (bleach, polident, microwave??)
Angular Cheilitis Treatment
1. Topical Antifungal Agents Rx: Clotrimazole cream 1% vs OR Rx: Nystatin-Triamcinolone Acetonide ointment or cream Disp: 15 g tube
Label: Apply to angles of mouth after meals and before bedtime
- Denture adjustment, reline, remake
