fungal infections Flashcards
what are fungi?
Eukaryotic cells (whereas bacteria is prokaryotic)
similar to mammalian cells
they do not respond to antibiotics like bacteria
they require anti-fungal tx
what is there a possibility of when treating patients with anti-fungal medications?
toxicity
(kills fungal cells - kills human cells) due to similarity
what is fungi hyphae ?
thread-like structures that make up the body of fungus.
what happens to fungi hyphae in extreme temps or when they get dehydrated?
they turn into spores which persist a long time in hostile environments
What percent of the population will carry oral commensals? (candida)
40%
but if someone is immune-suppressed or wears dentures 80%
why does candida usually live in the mouth without causing problems?
-mechanical protection from saliva and physical barrier of the epithelium.
-epithelial cells can recognise Candida cells are produce antimicrobials.
-candida can also be recognised by the inflammatory system
-complement activation- stimulates local inflammation which kills cells
-they can be phagocytized by white blood cells
-white blood cells can mount a T cell mediated immunity to fungal cells
what is the difference between bacteria and fungi immunity?
bacteria- antibody driven
fungi- cell mediate immunity
when do ppl get fungal infections
when there is a shift in balance
-saliva flow rate+competition+mucosal immunity keeps infection away
-candida load increase ex (from denture wearing)+ antibiotics (kill other bacteria in the mouth which can compete with candida)
or immune-suppressed (local+systemic steroids)
who is more susceptible to fungal infections?
-denture wearers
-dry mouth (low saliva)
-poor OH
-steroid inhaler (local immune suppression)
-topical/systemic steroids
-diabetic (more sugar around/ or systemic immune suppression)
what is chronic atrophic candidiasis? denture sore mouth/ denture stomatitis
-often asymptomatic
-full denture wearer
-old denture
-poor denture hygiene (leave it in most of the time take it out rarely)
-corresponds to fitting surface of upper denture
describe acute atrophic candidiasis (antibiotic sore mouth)
-uncomfortable
-after a course of antibiotics or steroids
-redness
-may be seen with pseudomembranous variety
-all over mouth not just denture fitting surface (in denture wearers)
describe pseudomembrane candidiasis (thrush)
-pt unwell / feels discomfort
-commonest form of acute candidiasis
-red white appearance in the mouth (red=inflammation)
-white plaques that can be wiped off leaving red raw area
common in
-newborn
-immune suppressed
-head/neck radiotherapy
-diabetic
-on steroids
describe chronic hyperplastic candidiasis
-commontly at the commissure/buccal mucosa (inner corner of the mouth)
-white patch that can’t be wiped off
-thickened mucosa (might be tender)
-biopsy- histology often shows dysplasia
if you see this on a pt do not just prescribe antifungals! refer for a biopsy
describe angular chelitis
-mixed candida and staphylococcal infection
-tend to have dentures or reduced facial height which produces creasing at the facial commissure – damp uncomfortable= develop thrush infection
who might candida infections be more problematic in?
HIV- acute pseudomembrane candidiasis
always think wh does this pt have candida
