Chapter 32 :: Lichen Planus

Question 1

Consistent features of lichen planus: 1. ________ cells in the dermis despite disease chronicity and 2. ________ cells in close proximity to dam- aged basal keratinocytes

Answer 1

1. CD4-positive T-helper (CD4-Th) cells
2. CD8-positive T-cytotoxic (CD8-Tc) cells

Question 2

The ________ is the effector cell of lichen planus.

Answer 2

CD8-Tc cell

Question 3

Upon costimulation by _______, CD4-Th cells release inflamma- tory cytokines, including _______, which leads to _______ activation and additional oligoclonal expansion.

Answer 3

LCs
IFN-γ
CD8- Tc

Question 4

Enhanced lym- phocyte reactivity to _______, a component of ________, has been found in patients with oral LTRs.

Answer 4

inorganic mercury
dental amalgam

Question 5

Modern theories encompass three major stages in the development of LP:

Answer 5

1. antigen recognition,
2. lymphocyte activation,
3. keratinocyte apoptosis.

A fourth stage, resolution, is a new and emerging facet of the disease

Question 6

Describe the epidemiology of LP.

Answer 6

Nearly two thirds of cases of lichen planus present between the ages of 30 and 60 years with a peak onset between 55 and 74 years.

Lichen planus is less com- mon at the extremes of age.

There is no clear sexual or racial predilection in lichen planus.

The age of onset is earlier in women.

Question 7

Describe the epidemiology of childhood LP.

Answer 7

Childhood lichen planus accounts for only 1% to 5% of the total lichen planus cases in the general popu- lation.

In Pacific Indians, childhood lichen planus is more common and accounts for nearly 20% of all cases.

No sexual predilection.

Peak onset 8-12 yo.

Question 8

______ is the most specific marker for lichen planus.

Answer 8

CXCL-9

Question 9

Characteristics of familial LP.

Answer 9

early onset
widespread
erosive or ulcerative disease
mucosal involvement
frequent relapses

Question 10

Multiple HLA haplotypes have been reported in famil- ial lichen planus, including ___ (4 items). In nonfamilial cases, ___ (6 items) are more common.

Answer 10

1. HLA-B27, Aw19, -B18, and -Cw8
2. HLA-A3, -A5, -A28, -B8, -B16, and Bw35

Question 11

___ is more common in patients with oral lichen planus alone, and ___ is more common with cutane- ous lichen planus alone. (HLA Types)

Answer 11

HLA-B8
HLA-Bw35

Question 12

___, fine, white and adher- ent reticulate scale, are noted in well-developed lesions.

Answer 12

Wickham striae

Question 13

The classic cutaneous lesions of lichen planus are ___ (describe).

Answer 13

well- marginated, dull red-violet, flat-topped, polygonal papules

Question 14

Clinical features of lichen planus correlate with the characteristic histological findings of lichen planus. Wickham striae correlate with ___. The dull red-violet color correlates with the ___.

Answer 14

orthokeratosis, epider- mal thickening, and an increased granular layer

combination of vascular dilation and pigment incontinence

Question 15

Distribution of LP

Answer 15

Symmetric over the extremities. The most common areas of involvement are the flexural wrists, arms, and legs. The proximal thighs, trunk, and neck are other common sites of involvement.

Question 16

Atypical areas for LP

Answer 16

face and palms

Question 17

Inverse lichen planus commonly involves the ___ (3).

Answer 17

axillae, groin, and inframammary region

Question 18

The presence of (characteristic) _________ should prompt consideration of an alternative diagnosis.

Answer 18

hypopigmentation

Question 19

Characteristic of hypertrophic LP

Answer 19

affects limited areas, such as the lower extremities, and is extremely pruritic

Question 20

Dermoscopic features of lichen planopilaris include: (6)

Answer 20

1. absence of follicular opening,
2. cicatricial white patches,
3. peripilar casts and perifollicular scale,
4. blue-gray dots,
5. perifollicular erythema,
6. polytrichia (two or three hairs)

Question 21

Histopathology of Actinic Lichen Planus:

Answer 21

1. a more brisk LTR relative to lichen planus pigmento- sus,
2. vacuolar changes,
3. pigment incontinence

Question 22

Hypertrophic Lichen Planus (verrucous) ddx:

Answer 22

1. keratinocyte carcinomas,
2. rupioid psoriasis,
3. rupioid syphilis,
4. reactive arthropathy,
5. cutaneous lupus ery- thematosus.

Question 23

___ is commonly among individuals with hypertrophic lichen planus

Answer 23

Chronic venous insufficiency

Question 24

Atrophic Lichen Planus ddx: (2)

Answer 24

lichen sclerosus et atrophicus
mycosis fungoides (MF)

Question 25

Hypertrophic Lichen Planus common sites:

Answer 25

anterior shins and interphalangeal joints

Question 26

Atrophic Lichen Planus common sites:

Answer 26

proximal lower extremity and trunk

Question 27

Vesiculobullous Lichen Planus occurs sec- ondary to an exuberant ___ and an exaggerated ___.

Answer 27

inflammatory response
Max-Joseph space

Question 28

Vesiculobullous Lichen Planus common sites:

Answer 28

lower extremities

Question 29

Erosive and Ulcerative Lichen Planus common sites:

Answer 29

feet
oral cavity

Question 30

___has been described in chronic lesions of ulcerative oral lichen planus.

Answer 30

SCC

Question 31

Follicular lichen planus occurs most commonly on the scalp and occurs in three distinct variants: (3)

Answer 31

lichen planopilaris,
frontal fibrosing alopecia,
Gram-Little-Piccardi- Lassueur syndrome (GLPLS)

Question 32

Lichen Planus Pigmentosus histopathology:

Answer 32

epidermal atrophy, a lymphocyte poor LTR, and pigment incontinence

Question 33

Lichen planus pigmentosus and ___ have significant overlapping features.

Answer 33

ashy dermatosis, or erythema dyschromicum per- stans

Question 34

Actinic Lichen Planus epidemiology:

Answer 34

young individuals of Middle Eastern descent and is most common in the spring and summer months

Question 35

Actinic LP most common sites:

Answer 35

1. face
2. dorsal hands, arms, and nape of the neck

Question 36

Actinic LP histopath:

Answer 36

a more brisk LTR relative to lichen planus pigmento- sus, vacuolar changes, and pigment incontinence

Question 37

Classic lichen planopilaris affects the __ scalp and consists of ___.

Answer 37

vertex
diffuse erythema with perifollicular hyperkeratosis and livid erythema

Question 38

GLPLS is a rare subtype characterized by __, __, __.

Answer 38

cicatricial alopecia of the scalp
nonscarring alopecia of the axilla and groin
follicular papules on the trunk and extremities

Question 39

__ is the end stage of follicular fibrosis caused by a primary inflammatory dermatosis such as lichen planus, lupus erythematosus, pustular scarring forms of folliculitis, fungal infections, sclero- derma, and sarcoidosis.

Answer 39

pseudopelade of Brocq

Question 40

Mucosal Lichen Planus common sites:

Answer 40

mouth, genitalia

Question 41

most common form of oral LP

Answer 41

reticular form

Question 42

most common site of reticular form of oral lichen planus

Answer 42

buccal mucosa > tongue > gingiva

Question 43

Erosive and ulcerative oral lichen planus is most on the ___

Answer 43

tongue

Question 44

___ is the most common cause of desquamative gingivitis

Answer 44

oral LP

Question 45

__ are similar clinically and histologically to oral lichen planus; however, with an identifiable cause

Answer 45

Oral lichenoid reactions (OLRs)

Question 46

A unique lichenoid eruption has been described on the tongues of individuals with HIV. This reaction is characterized by ___. The eruption usually follows ___ or ___ intake

Answer 46

bilateral reticular keratotic or atro- phic changes of the buccal mucosa and lichenoid atro- phic patches over the dorsal tongue
zidovudine, ketoconazole