4. Infections and idiopathic conditions of the oral mucosa Flashcards
What is the definition of infection?
Pathological state resulting from invasion of the body by pathogenic foreign species.
Give examples of infective agents apart from bacteria, virus and fungi?
Prions- no nucleic acids
Mycoplasma- no cell wall
Chlamydia- obligate intracellular parasites
Amoeba- Protozoa
Parasites
Name 3 features of viruses?
They do not have their own metabolism so cannot live on their own outside host cells.
Smaller than bacteria.
They have short DNA or RNA molecule, and genomes
What does obligate intracellular parasite mean?
They have their specific hosts and are unable to reproduce outside this host/cell as they do not have their own metabolism. eg. viruses
How do viruses cause damage?
Direct damage by replication, indirect damage by immune system fighting infection
Name 5 ways of detecting viruses?
- Immunofluorescence- detects antigens using specific antibodies
- PCR
- Serology- detects antibodies to viral antigens
- Culture from infected secretions or tissues
- Electron microscopy
What is herpetic stomatitis caused by?
HSV1 and HSV2
How is herpetic stomatitis spread? What age does it affect?
By contact or droplet spread
Common in children and young, but rare in under 6 years old
What is the early phase of infection of herpes simplex like?
May be subclinical and show no symptoms, or mild pharyngitis.
May be symptomatic and show gingivostomatitis.
How long is the incubation period for herpetic stomatitis?
5 days
What features do you get after prodromal symptoms of herpetic stomatitis, and how long does it take?
Occurs 1-2 days after prodromal symptoms
Numerous vesicles appear on mucosa and lips, vesicles ulcerate and can become infected leading to regional lymphadenitis, lesions crust, herpetic whitlow, herpetic keratitis, extra oral lesions on chin due to drooling.
Disappear after 10-14 days.
What is the histology of herpetic stomatitis like?
Empty spaces in the epithelium due to intraepithelial blistering
infected cells undergo ballooning degeneration
cells appear as giant cells as they fuse with neighbouring cells
inflammatory infiltration of epithelium and lamina propria
How does herpetic stomatitis recurrent infection occur?
The viral particle travel from the trigeminal ganglia through axons to nerve endings. They reinfect when in epithelial cells.
What is the most common recurrent infection of herpetic stomatitis?
Herpes labialis- causes lip vesicles after some hours of itching and tingling
What is the appearance of chicken-pox?
Small blisters/ulcers can appear in oral mucosa and soft palate preceding skin rash.
What is chicken pox histologically similar to?
HSV lesions
What is the reactivation of varicella zoster called, and what does it present as?
Shingles- prodromal symptoms followed by unilateral vesicle eruptions, painful, rupture leaving ulcerated areas.
Where is varicella zoster latent?
Sensory ganglia
What is the trigeminal involvement of varicella zoster like?
Mostly opthalmic division
If the 2nd or third division is involved, you can get toothache, facial pain, followed by vesicles
What is the sequel of varicella zoster virus?
Post herpetic neuralgia- when the virus hides in sensory ganglia it can cause fibrosis around the nerves.
What is Ramsay Hunt syndrome?
Occurs when shingles outbreak affects facial nerve- facial paralysis/taste, oral ulceration, external ear neuralgia, tinnitus, vertigo
What is measles caused by? What age group does it affect?
Paramyxovirus. Childhood.
What are the symptoms of measles?
Initially Koplik’s spots- on oral mucosa on labial side against molars - few to 100’s. Disappear when skin rash develops.
Then 1-2 weeks after infection you get prodromal symptoms- fever, cough, conjuctivitis, skin rash.
What infections are caused by Coxsackie type A virus?
Herpangina
Hand, foot and mouth disease
What are the features of herpangina?
Sore throat, dysphagia, fever, headaches, vomiting, abdominal pain
What are the oral features of herpangina?
Small vesicles 1-2mm, on tonsils, soft palate, uvula.
Ulcers with grey base and inflamed periphery.
What do the oral ulcers in herpangina look like?
Ulcers with grey base and inflamed periphery
How long does herpangina last?
2-3 days- self-limiting
What type of itis can you get in Herpangina?
Oropharyngitis
What are the symptoms of hand, foot and mouth disease?
Multiple ulcero-vesicular lesions in palate, tongue, buccal mucosa, skin, hands and feet
How long does hand, foot and mouth disease last?
3-6 days incubation period, infective until rash is gone
What is hand, foot and mouth disease caused by?
Coxsackie A16