Lichen Planus

Question 1

most common age of onset of LP:

Answer 1

• middle aged adults (peaks at 40-50)

Question 2

Male/female predominance

Answer 2

F>M

Question 3

Pathogenesis:

Answer 3

• auto reactive T-lymphocytes attack basal keratinocytes in the skin, mucous membranes, hair follicles and/or nail units. - viruses, medications, and contact allergens have been implicated as cause of this reaction.

Question 4

_____ is implicated in subset of oral ulcerative/erosive LP

Answer 4

Hepatitis C virus

Question 5

_____ is associated with oral LP, and bullous LP in children (otherwise uncommon presentation)

Answer 5

• Hepatitis B (vaccine)

Question 6

Contact allergens a/w oral LP:

Answer 6

• mercury amalgam, copper and gold

Question 7

treatment for oral LP caused by contact allergen?

Answer 7

• remove the allergen (mercury amalgam, copper, gold)

Question 8

Most common drugs implicated in drug induced LP:

Answer 8

• HCTZ, B-Blockers, ACE inhibitors, antimalarials, gold salts.

Question 9

Classic finding on lesions of LP:

Answer 9

• Wickham striae

Question 10

Drug induced LP clinically presents as_____ and spares the ______ regions of body

Answer 10

• more generalized, eczematous lesions, in a photo distribution - spares the oral mucosa and genitals

Question 11

Look for ______ on histopath for drug induced LP.

Answer 11

• eosinophils

Question 12

How long after drug can drug induced LP appear?

Answer 12

• up to one year!!

Question 13

LP presents clinically as:

Answer 13

• purple, pruritic, planar, papules and plaques

Question 14

LP lesions may exhibit______ phenomenon

Answer 14

• Koebner

Question 15

Most common sites of LP:

Answer 15

• oral mucosa is #1!!! - ventral wrists/forearms #2 - dorsal hands, shins, genitalia, presacral area and neck

Question 16

Histopathology of LP:

Answer 16

• wedge shaped hypergranulosis - orthohyperkeratosis - irregular acanthuses w/ “saw-toothed” rate ridges - vacuolar degeneration of the basal layer - apoptotic keratinocytes confined to basal layer with some in superficial dermis (Civatte bodies) - superficial dermal band-like (lichenoid) lymphocytic infiltrate

Question 17

With exception of drug induced and hypertrophic LP, histopath will lack _____.

Answer 17

• eosinophils

Question 18

With exception of drug-induced LP and oral LP, histopath will lack _____

Answer 18

• parakeratosis

Question 19

Graham-Little-Piccardi-Lasseru syndrome presents with:

Answer 19

• scarring alopecia of scalp caused by LPP - non-scarring hair loss at pubic and axillary regions - follicular papule that appear as keratosis pillars - and classic LP lesions of skin and mucosa Picture B.Little eating a Graham cracker with these symptoms.

Question 20

LP variants by location:

Answer 20

• genital - mucosal LP - nail LP - Inverse LP - palmoplantar LP - Lichen planopilaris

Question 21

___ % of patients with cutaneous LP will have oral lesions.

Answer 21

• 50%

Question 22

nail LP will present as:

Answer 22

• lateral thinning of nails - longitudinal ridges - pitting - dorsal pterygium

Question 23

LPP presents as:

Answer 23

• erythema and perifollicular scale around hair follicle that can lead to scarring alopecia

Question 24

LP variants based on appearance:

Answer 24

• classic - annular - atrophic - hypertrophic - ulcerative - linear - bulls - pemphigoides - pigmentosus

Question 25

Annular LP typically affects the ____ or \_\_\_\_

Answer 25

- penis or axilla

Question 26

atrophic LP usually occurs on ____ as \_\_\_\_

Answer 26

- legs - depressed or hyper pigmented lesions

Question 27

Ulcerative LP affects the \_\_\_\_

Answer 27

- palmoplantar surfaces

Question 28

Hypertrophic LP commonly occur on the _____ and are ____ (symmetric or asymmetric)

Answer 28

- shins and dorsal feet - symmetric - can be VERY PRURITIC

Question 29

Bullous LP presents as:

Answer 29

- blisters that arise within chronic LP lesions

Question 30

LP pemphigoides presents with blisters on ____ 2/2 ___ autoantibodies targeting \_\_\_\_

Answer 30

- blisters on uninvolved skin - IgG autoantibodies against BPAG 2

Question 31

LP pigmentosus presents as\_\_\_\_\_, and typically occurs in Fitzpatrick type ___ skin

Answer 31

- grey brown macule on sun exposed areas of face and neck - type 3/4 skin

Question 32

LP variants by cause:

Answer 32

- Actinic LP - Drug-induced LP

Question 33

Actinic LP occurs in _____ patient population and presents as:

Answer 33

- young middle eastern adults - red/brown plaques on sun-exposed areas of face, neck and extremities

Question 34

What do you NOT see on histology?

Answer 34

- parakeratosis or eosinophils - think of LP as the strict parent that does not let para or eos around!

Question 35

LP histology

Answer 35