(Ch11) Lichen planus and Lichnoid Flashcards
1
Q
Prevalence of LP
A
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
2
Q
Pathogenesis of LP
A
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
3
Q
Triggers of LP
A
- Idiopathic
- Viral
- Contact allergens
- Drugs
- Chronic GVHD
- Malignancy
- Vaccines
4
Q
Which viruses trigger LP
A
Hep C infection
Hep B vaccine
HHV- 6 and HHV-7
HSV and VZV
SARS-CoV-2
HPV
5
Q
Which virus As/w ulcerative/erosive LP
A
Hep C
6
Q
which trigger As/w oral and bollous LP in Children?
B -> Babbies -> Bollous
A
Hep B vaccine
7
Q
what percentage of cases are familial ?
A
10%
earlier age of onset, ↑ relapse rate, ↑ oral LP.
8
Q
Drugs triggers of LP
A
THAAQB
- TNFi
- HCTZ
- ACEi
- Antimalaria
-Quindine
-B-Blockers
9
Q
Allergens induce LP
A
Dental restorations:
Mercury
Amalgam
Gold
Copper
10
Q
what percentage of patient improve after removal of Allergen
A
95%
11
Q
if patch test is negative do you still need to remove trigger?
A
yes
75% improve with trigger removal despite -ve patch test likely due to irritant nature of the trigger
12
Q
What are Ps of LP
A
6Ps
Purple
Pruritic
Planus
Polygonal
Papule
plaque
13
Q
What is the most common location for LP
A
Oral mucosa 75% of cases
14
Q
percentage of oral LP developing cutaneous LP
A
10%
15
Q
cutaneous common locations for LP
A
ventral wrist and forearms
16
Q
List examples of vaccines As/w LP:
A
HBV vaccines
COVID-19 vaccines
influenza vaccines,
rabies vaccines
Interval few days to 5 months to develop LP , recommend to avoid further vaccinations.
17
Q
histopath features of LP
A
- Orthokeratosis
- Wedge shaped hypergranulosis
- Irregular acanthosis (saw tooth)
- Civatte bodies at basal layers of epidermis
- Lichnoid interface dermatitis
- Increase Max-Joseph spaces.
18
Q
Which cells if present in histopath indicate active disease LP?
A
Langerhans cells
19
Q
DIF for LP shows?
A
shaggy fibronogen at BMZ
colloid bodies often stain for IgM, IgA, IgG or C3
20
Q
Characteristic DIF finding of LP
A
colloid bodies often stain for IgM, IgA, IgG or C3
21
Q
which type of LP has eosin in histopth
A
Drug induced
Hypertrophic
22
Q
LP type with parakeratosis
A
Drug induced
Oral LP
23
Q
LP type with colloid bodies beyond basal layers ?
A
drug induced
similar to EM, SJS/TEN and FDE
this to differentiate those from regular LP
24
Q
LP vs lichen straitus in histopth
A
straitus has:
1. deep dermal inflammation/perifollicular (DLE)
- More lymphocyte exocytosis (PLEVA)
25
drug with longest latency to LP
Penicillamine 3y
B-blocker 1y
TNFi 3w-16m
Quinidine 4-6w
26
which ethnicity children has more LP
Arab
27
which primary immunodeficiency syndrome As/w LP
Good syndrome
- Thymomas + LP risk
28
Phases of pathogenesis of LP?
Induction phase
Evolution phase
1. Induction phase:
pathogens or endogenous ligands induce TLR of (keratinocytes and pDc)
↓
release type 1 IFNs (e .g . IFN-α)
to attract T cells
2. the evolution phase
-Attracted effector T cells release cytotoxic granules → perforin and granzyme B → apoptosis of keratinocytes
- Also Fas/FasL interactions → apoptosis of keratinocytes
29
Which autoimmune disease has no increased incidence of other autoimmune diseases
Lichen Planus
30
which time of the year LP improves at ?
Winter
31
Genes As/w LP
HLA-DR1
HLA-DR6
HLA-DR9
32
Which HLA gene As/w Hep C in LP
HLA-DR6
33
Variants of LP
1. Acute (exanthematous)
2. Actinic
3. Annular
4. Atrophic
5. Bullous
6. Drug induced
7. Genital
8. Hypertrophic
9. Oral
10. inverse
11. Linear
11. Nail
12. Overlap LP/LE
13. Palmoplanter
14. Pemphigoid
15. Pigmentousus
16. planopilaris/FFA
17. Graham-Little-Piccardi-Leusseur
34
Average latency for drug induced LP?
1y
35
Acute LP resolves within
3-9 months
36
Actinic LP
1. Middle eastern,indians and Africans
2. Young age
3. Sun exposed skin
4. onset in summer/spring
37
Annular LP
Axilla (MC)
Penis (Asymptomatic)
38
Atrophic LP
morphia like on LE
39
Bullous LP
Blister on longstanding LP lesion
due to expanded max-joseph space
40
Drug induced LP characteristics
vs Idiopathic
1. Older Age of onset (10y)
2. **Absence of**:
a- typical cutaneous location
b- mucosal lesions
c- Wickham straie
3. Generalized
4. Photo distributed
5. LP/Eczemtous/psoriastic lesions
6. Path
41
Drug induced LP path findings ?
Eosin
Parakeratosis
widespread apoptosis
42
Genital LP
Men: annular asym
Female: erosive and painful
43
what is the name of the syndrome of oral-genital LP
Vulvovaginal-Gingival syn
44
Which LP variants have higher risk of SCC
volvuvaginal
Hypertrophic
Oral erosive
45
Hypertrophic LP
LE
Average duration 6y
Eosin in path
risk of KA and SCC
46
Risk factor for hypertrophic LP
stasis dermatitis
47
Inverse LP
Axilla hyperpigmentation
48
LP variants with axiliary involvement ?
Inverse LP
Annular
49
Linear LP
Spontaneous no koebner
young adults
likely Somatic Mosaic
50
Oral LP
1. Reticular: MC, Asymptomatic , Bil buccal
2. Atrophic, Erosive and Bollous: F, painful and SCC+/-GI&genital
3. Hep C: tongue
4. Smokers: plaque type
51
Nail LP classic findings
1. Longitudinal ridging
2. Dorsal pterygium
3. Fissuring
4. Lateral thinning
kids may have 20 nail dystrophy
52
LP/LE location
Acral Bullae
53
LP pemphigus
1. appears months after LP
2. uninvolved skin
3. Circulating IgG against BPAG2
4. younger age
54
LP pigmentosus
- sun exposed skin
- maybe after application of photoseitizers (mustard oil)
- no preceding erythema
55
LP pigmentosus vs EDP
only difference on path but:
LP: sun exposed and other LP lesions
EDP: truncal, younger age
56
LPP characteristics
perifollicular hyperkeratosis with violacious rim
older female variant FFA
57
features of Graham-Little-Piccardi-Leusseur
1. Scalp scarring alopecia
2. Axillary and pubic **non scarring** Alopecia
3. LP
4. Spiny follicular papules on skin
58
Systemic tx for Generalized LP
MTX
Metronidazole
phototx
59
Rx for resistant LP
Acetritin
CsA
60
LPP tx
HCQ
61
LP variants with higher likelihood of persistence ?
Hypertrophic
oral (especially ulcerative)
nail
62
LP prognosis
resolves in 1-2y
63
Variant of LP associated with T cell lymphoma
Lichenoid granulomatus dermatitis
triggered by meds
As/w T cell lymphoma , Sarcoidosis and RA
64
How to diagnose Lichenoid granulomatus dermatitis
Biopsy showing granuloma
Multinucleated giant cells
65
which group of patient at higher risk for Lichen striatus?
Atopic Female kids
66
Can Lichen striatus recur?
NO recurrence, ONLY relapse.
67
Prognosis of Lichen striatus
Self-limited ~1-2 Yrs
Leaves PIHypopigmentation
68
Nail signs of Lichen striatus
Onycholysis, splitting, fraying +/- nail loss.
69
Tx of Lichen striatus including nail?
TCS + occlusion
Tacrolimus in nail dystrophy
70
Ddx of Lichen striatus
Linear LP
Linear porokeratosis
Linear psoriasis
ILVEN
linear lichen sclerosus
linear Darier
Blaschkitis (Trunk > extremities)
Linear GVHD
71
Conditions As/w Lichen nitidus
1. Down syndrome
2. Crohn’s
3. HBV
4. HIV
5. AD
72
Distribution of Lichen nitidus
flexors arms, chest, abdomen, genitalia & dorsal hands.
Koebner phenomenon
73
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
74
what is characteristic histopath sign of Lichen nitidus?
ball&claw configuration Well-circumscribed lymphocytic infiltrate
parakertosis
Atrophic epidermal cap
Absent granular layer
Eosin
75
Lichen nitidus prognosis?
Self-limited ~1-8 Yrs
76
Lichen nitidus Tx?
TCS + Ani-Histamines if itchy
Tacrolimus for peds
Generalized → phototherapy
DNCB
77
Variants of Lichen nitidus?
Vesicular and hemorrhagic
Generalized
Palmoplantar
Linear
Follicular spines
Perforating
nail
oral
78
Erythema Dyschromicum Perstans associated gene
HLA-DR4
79
Erythema Dyschromicum Perstans epidemiology
M = F
At 1st - 3rd decade of life
Skin type 4/5
80
Erythema Dyschromicum Perstans As/w
? Inhelation, contact or ingestion of pollutants: Ammonium nitrate, benzodiazepines, Pesticides
penicillin, infestations
HIV, whipworm
Thyroid
81
Which lichenoid dermatitis present with oval **macules** follows cleavage lines ?
Erythema Dyschromicum Perstans
(symmetric)
82
Erythema Dyschromicum Perstans histopath
Pigment incontinence
lichenoid dermatitis
83
Ddx of Erythema Dyschromicum Perstans
PIH from:
Lichenoid drug eruption
PR (△ Epidermal pigment)
Parapsoriasis
FDE (△circular & brown)
84
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
85
Which lichenoid dermatitis has linear & reticulated pattern plaque that resolve in summer?
Keratosis Lichenoides Chronica
86
how does Keratosis Lichenoides Chronica present on the face
greasy scaly eruption on upper face (seb derm-like or psoriasiform)
87
Annular Lichenoid Dermatitis
Over groin & flanks
F = M
Kids + young adults
At 5–22 Yrs
88
Which histopathologic feature of lichen planus corresponds to whickham striae?
Hypergranulosis
89
What are 2 trichoscopic features of lichen planus?
Perifollicular erythema
Follicular spines (keratotic plugs)
Scarring
90
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
91
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
92
What are 2 systemic investigations to consider with patients affected by oral erosive lichen planus?
Endoscopy
Hepatitis C serology
93
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
94
How can lichen striatus be differentiated from lichen planus on pathology?
Lichen striatus affects adnexal structures.
95
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
96
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
97
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
