(Ch11) Lichen planus and Lichnoid Flashcards
Prevalence of LP
Oral 4%
Cutaneous 1%
Peak in middle aged F
75% overall pt have oral
75% of cutaneous LP pt —> have oral LP.
70% of vulvar LP pt —> have vaginal LP
10% of patients have nail LP
10% of oral –> have cutaneous
10% familial
Pathogenesis of LP
Pathogenesis due to CD8+ T-cells mediated autoimmune induced apoptosis of basal keratincytes from cross reaction with exogenous or endogenous antigens:
-viruses
-bacteria - local microbiome
-drugs
-contact allergens
-Autoantigens (like tumour antigens )
-Sweating disturbance
Triggers of LP
- Idiopathic
- Viral
- Contact allergens
- Drugs
- Chronic GVHD
- Malignancy
- Vaccines
Which viruses trigger LP
Hep C infection
Hep B vaccine
HHV- 6 and HHV-7
HSV and VZV
SARS-CoV-2
HPV
Which virus As/w ulcerative/erosive LP
Hep C
which trigger As/w oral and bollous LP in Children?
B -> Babbies -> Bollous
Hep B vaccine
what percentage of cases are familial ?
10%
earlier age of onset, ↑ relapse rate, ↑ oral LP.
Drugs triggers of LP
THAAQB
- TNFi
- HCTZ
- ACEi
- Antimalaria
-Quindine
-B-Blockers
Allergens induce LP
Dental restorations:
Mercury
Amalgam
Gold
Copper
what percentage of patient improve after removal of Allergen
95%
if patch test is negative do you still need to remove trigger?
yes
75% improve with trigger removal despite -ve patch test likely due to irritant nature of the trigger
What are Ps of LP
6Ps
Purple
Pruritic
Planus
Polygonal
Papule
plaque
What is the most common location for LP
Oral mucosa 75% of cases
percentage of oral LP developing cutaneous LP
10%
cutaneous common locations for LP
ventral wrist and forearms
List examples of vaccines As/w LP:
HBV vaccines
COVID-19 vaccines
influenza vaccines,
rabies vaccines
Interval few days to 5 months to develop LP , recommend to avoid further vaccinations.
histopath features of LP
- Orthokeratosis
- Wedge shaped hypergranulosis
- Irregular acanthosis (saw tooth)
- Civatte bodies at basal layers of epidermis
- Lichnoid interface dermatitis
- Increase Max-Joseph spaces.
Which cells if present in histopath indicate active disease LP?
Langerhans cells
DIF for LP shows?
shaggy fibronogen at BMZ
colloid bodies often stain for IgM, IgA, IgG or C3
Characteristic DIF finding of LP
colloid bodies often stain for IgM, IgA, IgG or C3
which type of LP has eosin in histopth
Drug induced
Hypertrophic
LP type with parakeratosis
Drug induced
Oral LP
LP type with colloid bodies beyond basal layers ?
drug induced
similar to EM, SJS/TEN and FDE
this to differentiate those from regular LP
LP vs lichen straitus in histopth
straitus has:
1. deep dermal inflammation/perifollicular (DLE)
- More lymphocyte exocytosis (PLEVA)
drug with longest latency to LP
Penicillamine 3y
B-blocker 1y
TNFi 3w-16m
Quinidine 4-6w
which ethnicity children has more LP
Arab
which primary immunodeficiency syndrome As/w LP
Good syndrome
- Thymomas + LP risk
Phases of pathogenesis of LP?
Induction phase
Evolution phase
- Induction phase:
pathogens or endogenous ligands induce TLR of (keratinocytes and pDc)
↓
release type 1 IFNs (e .g . IFN-α)
to attract T cells - the evolution phase
-Attracted effector T cells release cytotoxic granules → perforin and granzyme B → apoptosis of keratinocytes
- Also Fas/FasL interactions → apoptosis of keratinocytes
Which autoimmune disease has no increased incidence of other autoimmune diseases
Lichen Planus
which time of the year LP improves at ?
Winter
Genes As/w LP
HLA-DR1
HLA-DR6
HLA-DR9
Which HLA gene As/w Hep C in LP
HLA-DR6
Variants of LP
- Acute (exanthematous)
- Actinic
- Annular
- Atrophic
- Bullous
- Drug induced
- Genital
- Hypertrophic
- Oral
- inverse
- Linear
- Nail
- Overlap LP/LE
- Palmoplanter
- Pemphigoid
- Pigmentousus
- planopilaris/FFA
- Graham-Little-Piccardi-Leusseur
Average latency for drug induced LP?
1y
Acute LP resolves within
3-9 months
Actinic LP
- Middle eastern,indians and Africans
- Young age
- Sun exposed skin
- onset in summer/spring
Annular LP
Axilla (MC)
Penis (Asymptomatic)
Atrophic LP
morphia like on LE
Bullous LP
Blister on longstanding LP lesion
due to expanded max-joseph space
Drug induced LP characteristics
vs Idiopathic
- Older Age of onset (10y)
-
Absence of:
a- typical cutaneous location
b- mucosal lesions
c- Wickham straie - Generalized
- Photo distributed
- LP/Eczemtous/psoriastic lesions
- Path
Drug induced LP path findings ?
Eosin
Parakeratosis
widespread apoptosis
Genital LP
Men: annular asym
Female: erosive and painful
what is the name of the syndrome of oral-genital LP
Vulvovaginal-Gingival syn
Which LP variants have higher risk of SCC
volvuvaginal
Hypertrophic
Oral erosive
Hypertrophic LP
LE
Average duration 6y
Eosin in path
risk of KA and SCC
Risk factor for hypertrophic LP
stasis dermatitis
Inverse LP
Axilla hyperpigmentation
LP variants with axiliary involvement ?
Inverse LP
Annular
Linear LP
Spontaneous no koebner
young adults
likely Somatic Mosaic
Oral LP
- Reticular: MC, Asymptomatic , Bil buccal
- Atrophic, Erosive and Bollous: F, painful and SCC+/-GI&genital
- Hep C: tongue
- Smokers: plaque type
Nail LP classic findings
- Longitudinal ridging
- Dorsal pterygium
- Fissuring
- Lateral thinning
kids may have 20 nail dystrophy
LP/LE location
Acral Bullae
LP pemphigus
- appears months after LP
- uninvolved skin
- Circulating IgG against BPAG2
- younger age
LP pigmentosus
- sun exposed skin
- maybe after application of photoseitizers (mustard oil)
- no preceding erythema
LP pigmentosus vs EDP
only difference on path but:
LP: sun exposed and other LP lesions
EDP: truncal, younger age
LPP characteristics
perifollicular hyperkeratosis with violacious rim
older female variant FFA
features of Graham-Little-Piccardi-Leusseur
- Scalp scarring alopecia
- Axillary and pubic non scarring Alopecia
- LP
- Spiny follicular papules on skin
Systemic tx for Generalized LP
MTX
Metronidazole
phototx
Rx for resistant LP
Acetritin
CsA
LPP tx
HCQ
LP variants with higher likelihood of persistence ?
Hypertrophic
oral (especially ulcerative)
nail
LP prognosis
resolves in 1-2y
Variant of LP associated with T cell lymphoma
Lichenoid granulomatus dermatitis
triggered by meds
As/w T cell lymphoma , Sarcoidosis and RA
How to diagnose Lichenoid granulomatus dermatitis
Biopsy showing granuloma
Multinucleated giant cells
which group of patient at higher risk for Lichen striatus?
Atopic Female kids
Can Lichen striatus recur?
NO recurrence, ONLY relapse.
Prognosis of Lichen striatus
Self-limited ~1-2 Yrs
Leaves PIHypopigmentation
Nail signs of Lichen striatus
Onycholysis, splitting, fraying +/- nail loss.
Tx of Lichen striatus including nail?
TCS + occlusion
Tacrolimus in nail dystrophy
Ddx of Lichen striatus
Linear LP
Linear porokeratosis
Linear psoriasis
ILVEN
linear lichen sclerosus
linear Darier
Blaschkitis (Trunk > extremities)
Linear GVHD
Conditions As/w Lichen nitidus
- Down syndrome
- Crohn’s
- HBV
- HIV
- AD
Distribution of Lichen nitidus
flexors arms, chest, abdomen, genitalia & dorsal hands.
Koebner phenomenon
DDx Lichen nitidus
LP
Guttate lichen sclerosus
Lichen spinulosus
Frictional lichenoid dermatitis
Papular eczema
Verruca plana,
Lichen striatus
Colloid milium
Papular sarcoidosis
Lichenoid 2ry syphilis
what is characteristic histopath sign of Lichen nitidus?
ball&claw configuration Well-circumscribed lymphocytic infiltrate
parakertosis
Atrophic epidermal cap
Absent granular layer
Eosin
Lichen nitidus prognosis?
Self-limited ~1-8 Yrs
Lichen nitidus Tx?
TCS + Ani-Histamines if itchy
Tacrolimus for peds
Generalized → phototherapy
DNCB
Variants of Lichen nitidus?
Vesicular and hemorrhagic
Generalized
Palmoplantar
Linear
Follicular spines
Perforating
nail
oral
Erythema Dyschromicum Perstans associated gene
HLA-DR4
Erythema Dyschromicum Perstans epidemiology
M = F
At 1st - 3rd decade of life
Skin type 4/5
Erythema Dyschromicum Perstans As/w
? Inhelation, contact or ingestion of pollutants: Ammonium nitrate, benzodiazepines, Pesticides
penicillin, infestations
HIV, whipworm
Thyroid
Which lichenoid dermatitis present with oval macules follows cleavage lines ?
Erythema Dyschromicum Perstans
(symmetric)
Erythema Dyschromicum Perstans histopath
Pigment incontinence
lichenoid dermatitis
Ddx of Erythema Dyschromicum Perstans
PIH from:
Lichenoid drug eruption
PR (△ Epidermal pigment)
Parapsoriasis
FDE (△circular & brown)
Erythema Dyschromicum Perstans prognosis and tx
? Spontaneous resolution; recur q2–3 Yrs
Resistent to Rx
Sun protection, TCS, retinoids, vitamin C/A, chemical peels, dapsone, antimalarials, Clofazimine, Griseofulvin, SCS, Isotretinoin, TXA
Which lichenoid dermatitis has linear & reticulated pattern plaque that resolve in summer?
Keratosis Lichenoides Chronica
how does Keratosis Lichenoides Chronica present on the face
greasy scaly eruption on upper face (seb derm-like or psoriasiform)
Annular Lichenoid Dermatitis
Over groin & flanks
F = M
Kids + young adults
At 5–22 Yrs
Which histopathologic feature of lichen planus corresponds to whickham striae?
Hypergranulosis
What are 2 trichoscopic features of lichen planus?
Perifollicular erythema
Follicular spines (keratotic plugs)
Scarring
In which other dermatologic condition can lichen planus-like lesions be seen?
Lichen planus-lupus overlap
Lichen planus pemphigoides
Graft-versus-host disease
Lichenoid drug eruption
Paraneoplastic pemphigus
What dermatologic conditions cause dorsal pterygium? What are 3 classic conditions that cause ventral pterygium?
Dorsal pterygium: lichen planus, graft-versus-host disease, porphyria
Ventral pterygium: systemic scleroderma
What are 2 systemic investigations to consider with patients affected by oral erosive lichen planus?
Endoscopy
Hepatitis C serology
A 52 year-old female patient is assessed for recurrent oral lichen planus. She is also investigated for repeated pneumonias and a recent chest X-ray reveals a mediastinal mass. What is the suspected syndrome?
Good’s syndrome: thymoma, oral lichen planus, immunodeficiency
How can lichen striatus be differentiated from lichen planus on pathology?
Lichen striatus affects adnexal structures.
How does the prognosis of erythema dyschromicum perstans differ in children as opposed to adults?
Spontaneous resolution is seen in children within 2-3 years
Persistent in adults
What are 3 clinical features differentiating lichen planus pigmentosus from erythema dyschromicum perstans?
Lichen planus pigmentosus:
Skin types III-IV
4-5th decade of life
Photodistribution or intertriginous
20% co-existence with classic lichen planus
Erythema dyschromicum perstans:
Skin types IV-V, Latin Americans
1-3rd decade of life
Sun protected distribution (trunk, proximal arms) + neck
Uncommon erythematous margins
What are 5 clinical features of keratosis lichenoides chronica?
Violaceous keratotic lichenoid papules
Linear or reticulated pattern (resembles Chinese characters)
Involves limbs and trunk
Symmetric
Chronic and progressive course;
occasionally lesions regress during summer or with age
Resistant to treatment