Immune-mediated Disorders Of Oral Mucosa Flashcards
Layers of SSE
Bottom : Stratum Basale
Stratum spinosum
Top/ stratum superficiale
What category of disease is lichen planus?
Type IV Hypersensitivity
What are the two subtypes of Oral Lichen Planus
Reticular Lichen Planus
– Usually asymptomatic
– Interlacing white lines
(Wickham’s striae)
– History of waxing and waning
Erosive
– Symptomatic, always paunful
– Ulcerated mucosa
– May be restricted to gingiva
In order, what are the diseases that cause desquamative gingivitis?
- MOST COMMON CAUSE: erosive lichen planus, and Linchenoid mucositis
- Mucous membrane pemphigoid
- Pemphigus vulgaris
- Graft vs. host disease: pt immune system responding negatively to bone marrow transplant
- Systemic lupus erythematous
- Discoid lupus erythematosus
Lichen planus: histologic hallmarks
Small red circles in stratum basale: colloid or cevatte bodies, which are apoptotic keratinocytes
Below basement membrane: abundance of lymphocytes (CD8+)
Diseases that look like Lichen Planus
Local: Lichenoid mucositis (contact allergy or drug allergy)
Systemic: SLE, graft vs. host
Common causes of lichenoid mucositis, treatment, and notable histology
Medications, flavoring agents, dental materials
Treatment: topical corticosteroids to suppress lymphocytes
Notable histology: perivascular infiltrate/perivasculitis (lymphocytes wrapped around blood vessels) as well as the same lymphoctes under BM like in LP
Hemidesmosome proteins
Cytokeratins in cytoplasm….
Connected to Plextin, BP180 and BP 230…
which connect to Integrin alpha6 beta4 (crosses membrane)…
Which extracellularly connects to laminin 5 in basement membrane
Benign mucous membrane pemphigoid (BMMP) fast facts
- autoimmune, works like Type II hypers.
- targets hemidesmosomes (sub basilar clevage)
- limited to mucous membranes
- more in older women
- lesions heal with scarring
- opthalmology consult mandatory
- treatment with topical or systemic meds
Effects of untreated BMMP on eyes
It doesn’t affect the eyeball directly, it does affect conjunctiva
- inverted eyelids
- eyelashes rub against cornea, then fall off
- “symblepharon”: scar tissue between conjunctiva and eyeball
- progresses to “ankyloblepharon”: fixed globe
- eventually, blindness
Results of Direct IF with anti-IgG tags on BMMP patient biopsy
Distinct line along basilar membrane. Not pathognomonic but it is disgnostic
Desmosome proteins
- Tonofibrils (bundles of tonofilaments) connect to…
- Intracellular thickenings composed of desmoplakin and plakoglobin, which are continuous with…
- Desmoglein and desmocollin that penetrate intercellular space, and.::
- Attach to their counterparts from opposite cells
Pemphigus Vulgaris fast facts
- no sex predilectjon
- fragile vesicles or bullae (Positive Nikolsky sign: induce a blister just by rubbing mucosa)
- minor trauma significantly damages skin or mucosa
- dysphonia, dysphagia
- like a type II hyp, against Desmoglein 3
(No significant effect on eyes) - treat with systemic meds
Common histo of pemphigus vulgaris
- suprabasular clevage
- acantholysis: cells separate
- Tzanck cells: free floating cells
(Remember, both of those last two are also seen in herpes) - basal cells look like tombstones
Direct IF and Indirect IF of Pemphigus Vulgaris
Direct IF: network of lace like lines is pathognomonic for PV
Indirect IF: same thing on control tissue; the auto AB is in circulation
