Lichen Planus Flashcards
what is lichen planus?
a common inflammatory immunologically mediated mucotaneous disorder which can affect stratified squamous epithelium
what are the types of lichen planus?
reticular
plaque like
papular
atrophic/ erosive
ulcerative
what are the histological findings for LP?
T cell infiltrate into basement membrane area of connective tissue
lymphocytic band hugging basement membrane
what are the histological findings for lichenoid tissue reaction?
chronic inflammatory cell infiltrate
saw tooth rete ridges
basal cell damage
patchy acanthosis
parakeratosis
what is a lichenoid tissue reaction?
the term used when lesions are clinically and histologically similar to lichen planus but have a cause eg dental materials, Hep C infection, drugs (eg NSAIDs), systemic disease (eg graft versus host)
what is the cause of LP and its pathogenesis?
often, cause is unknown
epithelial damage mediated by T cells directed against basilar keratinocytes
antigens responsible are unknown
epithelial atrophy can also occur, leading to ulceration
what are the clinical features of lichen planus?
oral LP may occur in isolation or may precede lesions on other stratified squamous epithelium
mostly white lesions which occur bilaterally
may present with desquamative gingivitis
often asymptomatic but may be pain from erosive/ atrophic areas
mild oral discomfort/ burning sensation may be described
what is the malignant potential for OLP
small malignant potential
<1-3%
most commonly in non-reticular lesions eg erosive
how does LP present on the skin
as skin rash
Purple
Polygonal
Puritic
papules (often with wickhams striae)
how is LP diagnosed?
diagnosed from clinical features
exclusion of lichenoid reaction - drug induced, dental materials, diabetes mellitus, graft v host disease, HIV/ Hep C
skin testing for hypersensitivity
firm diagnosis relies on biopsy of lesional tissue for H&E staining and aided by DIF
what is the difference between the clinical presentation of LP and lichenoid reactions?
lichenoid reactions are often unilateral, may be associated with erosions and resolve on discontinuation of offending drug etc
how often do patients with OLP present with other sites involved?
up to 50%
can be before, during or after
what sites does OLP affect?
buccal mucosa - most common
gingiva (desquamative gingivitis)
tongue
lips
palate
how does gingival lichen planus typically present?
can be found in isolation - if this is the case, termed desquamative gingivitis
similar clinical presentation as gingival pemphigoid (histological differences)
red, inflamed, atrophic gingiva
how does tongue OLP typically present?
dorsum - usually idiopathic causing loss of papilla and smooth tongue surface
lateral - may have drug/ amalgam trigger (look at position of tongue in rest)
