12- Lichen Planus And Related

Question 1

Pruritic, inflammatory disease of the skin, mucous membranes (conjucntival vulval otic esophageal) and hair follicles

Small flat topped polygonal papules
Erythematous—violaceous—hyperpigmented
Glistening and dry with adherent scales
Pruritus may precede lesions

(+) Koebner phenomenon

Answer 1

Lichen planus

Question 2

Nail changes in lichen planus that is most common

Answer 2

Longitudinal ridging and splitting - 90%

Question 3

Characteristic of lichen planus of the nails

Answer 3

Pterygium formation

- nail matrix destroyed by inflammation and replaced by fibrosis

Question 4

Verrucous plaques with scaling with small flat topped polygonal papules at the edge

Anterior lower leg below the knee is the sole srea of involvement in most patients

Answer 4

Hypertrophic lichen planus

Question 5

Most common form of mucosal LP

Answer 5

Oral (buccal 90% gingiva 50% tongue 40%)

Question 6

Most common pattern in oral lichen planus

Answer 6

Ulcerative 40%

Question 7

Most common cause of oral lichenoid lesion (histologically identical to oral LP but from a different cause)

Answer 7

Metals in dental amalgams (mercury, copper, zinc and tin)

Question 8

Oral LP and vulvovaginal LP may increase the risk of developing what type of cancer

Answer 8

SCC

Question 9

Three liver conditions have been associated with LP

Answer 9

Hepatits C virus
Hepatitis B immunization
Primary biliary cirrhosis

Question 10

Patients who have typical LP then months later develop blistering on lesions and normal skin

Answer 10

Lichen planus pemphigoides

Question 11

LP pemphigoides has been triggered by medications like

Answer 11

ACE inhibitors

IFN
HBV
PUVA

Question 12

Lichen planus is characterized by an immunologic reaction mediated by _______ cells that induce keratinocytes to undergo apoptosis

Answer 12

CD8 T cells

Question 13

Elevated labs in LP

Answer 13

Dyslipidemia- increased LDL, Triglycerides, decreased HDL

Increased inflammatory markers
Insulin resistance

Question 14

Treatment for LP

Answer 14

Topical steroids/intralesional injection

Phototherapy
Oral retinoids- hypertrophic/palmoplantar LP
Enoxaparin 3mg subQ once a week- oral LP
Antimalarials

Immunosuppressive- severe

Question 15

Lichen planus involving the follicular apparatus

Most cases involve the scalp
Important cause of cicatricial alopecia

Answer 15

Lichen planopilaris (LPP)

Question 16

Rare chronic dermstosis
Papulonodular and hyperkeratotic lesions covered with gray scales

Favor extremities and buttocks
Coalesce to form linear and reticular warty lichenoid lesions

Infundibulocentric and acrosyringocentric

Answer 16

Keratosis lichenoides chronica

Question 17

Minute, shiny, flat topped, pale, exquisitely discrete, uniform papules, rarely larger than 1-2mm

Pruritus minimal or absent
(+) Koebner phenomenon
Common in penis, forearms and dorsal hands
Keratotic plug in the center of lesions of palmoplantar variant

Answer 17

Lichen nitidus

Question 18

Self limited eruption in young children

Small papules that are erythematous and slightly scaly

Over a few weeks coalesce and progress down to extremity or trunk following lines of Blaschko
Usually asymptomatic, spontaneously resolve without scarring in 1 year

Answer 18

Lichen striatus

Question 19

White polygonal flat topped papules, plaques or atrophic patches involves genital areas

May be surrounded by erythematous to violaceous halo
Skin smooth slightly wrinkled, soft and white
Severe itching
Normal anatomic strictures may be obliterated
Postmenopausal preferentially affected

Answer 19

Lichen sclerosus

Question 20

Autoimmune diseases associated with lichen sclerosus

Answer 20

Thyroid disease 
Vitiligo
Morphea
Pernicious anemia
Alopecia areata

Question 21

Treatment of lichen sclerosus

Answer 21

Clobetasol ointment OD then tapered to once or twice a week or to lower strength