lichen planus Flashcards
what is the etiology of lichen planus ?
t cell mediated autoimmune disorder
associated with stress
genetic predisposition
liver disease - hepatitis C
koebenrization
drugs associated :
gold
quinine
hydroxyquinine
captopril these cause a lichenoid rash
what is koebrnizatoin ?
the appearance of new skin lesions around previous lines of trauma that were previously unaffected
what diseases show the koeebner phenomenon
Vitiligo
Viral warts
psoriasis
lichen planus
what are the different types of Lichen planus ?
mucosal lichen planus
cutaneous lichen planus
lichen planpilaris
lichen planus of the nails
lichenoid drug eruption
lichen planus pigmentosus
bullous lichen planus
what is the presentation of cutaneous lichen planus ?
6Ps
purple
planar
polished
papular
pruritic
polygonal
what is the distribution of LP ?
mostly at the
wrists
ankles
lower back
in an annular or acitinic Arrangement ( sun exposed areas )
but may be scattered,
clustered, linear,
what is characteristic about LP plaques ?
have white striae called Wickham striae
where is mucosal lichen planus commonly seen ?
oral mucosa
vulva
glans of the penis
what is the presentation of mucosal lichen planus ?
painless white streaks in a lacy pattern
painful ulcers ( erosive lichen planus )
what is the most serious complication associated with erosive lichen planus ?
squamous ceell carcinoma
how does mucosal lichen planus present in the penis ?
classical papules in a ring around the glans
what is the presentation of lichen planpilaris ?
tiny red follicular papules which may eventually lead to scarring alopecia due to destruction of the hair follicles
what does lichen planus of the nails look like ?
onycholysis ( nail separates from the nail bed )
pterygium
grooves and ridges
what is pterygium ?
over growth of the proximal nail fold onto the nail bed
what is the presentation of lichen planus pigmentosus?
ill defined greyish brown spots
appear of the neck , face , limb and trunks
usually provoked by sun exposure but can present in areas like the armpit ( sun protected areas )
appear without an inflammatory phase
what is the presentation of lichenoid drug eruptions ?
Lichen planus-like rash caused by medications
may be asymptomatic , may be itchy
absent wickham striae
what is bullous lichen planus ?
a rare subtype
where bullous lesions appear in the context of pre existing LP lesions
how is a diagnosis of LP made ?
clinical features
biopsy
Direct immunofluorescent at the base of the epidermis
hepatitis markers
what is the management of LP ?
Topical
. Potent topical. Steroids
. Topical calcineurine inhibitors - immunosupp
. Topical retinoids
. Intralesional steroid injections
Systemic
. Steroids
. Hydroxychloroquine ( oral LP )
. Acitretin
. Phototherapy
what is Pityriasis Rosea ?
acute exanthematous eruption
Pityriasis - flaking or scaling of the skin
Rosea - pink in colour
age group affected in Pityriasis Rosea ?
children and young adults
what is the aetiology of pityriasis rosea ?
aetiology unclear
Triggered by upper respiratory viral infection (cough, cold, sore throat)
what is the C/P of pityriasis Rosea ?
herald patch
then a secondary rash that appear a few days after the herald patch
what is the distribution of the 2ry rash that comes with pityriasis rosea ?
scaly patches follows thee lines of the dermatomes
xmas tree appearance
chest and back , arms and neck ( T shirt )
may be veery itchy and may not itch at all
what is the dddx of pityriasis rosea ?
fungal infection - tinea corporis
drug rash
secondary syphillus ( palms would be affected)
seborrheic dermatitis ( oily and scaly )
nummular eczema ( no herald patches )
viral exanthems
what is the management of pityriasis rosea ?
Rash clears up in about six to twelve weeks
* shower with plain water and bath oil, aqueous cream,
* Apply moisturising creams to dry skin
Medical
-Topical steroid may reduce the itch
-Oral Acyclovir
- Phototherapy
fate of lichen planus ?
Most lesions undergo spontaneous healing within 6m with post inflammatory hyperpigmentation.
