Lichen Planus

Question 1

Name clinical variants of LP (total 9)

Answer 1

• Annular, blacks, penis and scrotum
• Linear, secondary to trauma
• Hypertrophic, shins and interphalangeal joints, most pruritic, heals with scar and dyspigmentation
• Atrophic, rare, white/bluish papules/plaques with central atrophy, lower exits and trunk, resembles lichen sclerosis et atrophicus
• Vesiculobullous, rare, within lesions of LP
• Erosive Ulcerative, SCC risk, desquamative gingivitis
• Follicular (lichen planopilaris), trunk and medial aspects of proximal exits, scalp with cicatricial alopecia
• Lichen Planus Pigmentosus, dark brown macules in sun-exposed areas and flexural folds, similar to erythema dyschromicum perstans
• Actinic, affects sun-exposed areas, over exits

Question 2

Erosive mucous membrane disease (LP)

Answer 2

• Hepatitis C infection

Question 3

Graham-Little-Piccardi-Lassueur syndrome

Answer 3

• Follicular LP of skin and/or scalp
• Multifocal cicatricial alopecia of scalp
• Nonscarring alopecia of axillary and pubic areas

Question 4

Sites of involvement

- Palmoplantar

Answer 4

• Yellow, compact keratotic papules and papulonodules on lateral margins of fingers and hand surfaces

Question 5

Sites of involvement

- Inverse

Answer 5

• Rare, flexural such as axilla, under breast, and groin, reddish-brown and discrete papules

Question 6

Sites of involvement

- Nails, classic findings

Answer 6

• 20 nail dystrophy (trachyonychia)
• Classically, dorsal pterygium
• Pits common

Question 7

Sites of involvement

- Mucosal

Answer 7

• Mouth, vagina, esophagus, conjunctiva, urethra, anus, nose, larynx
• Glans penis most common (annular lesion)
• Leukoplakia/erythroplakia, erosive, or generalized desquamative vaginitis
• Conjunctival LP, cicatricial conjunctivitis

Question 8

Sites of involvement

- Scalp

Answer 8

• End-stage: scarring alopecia

Question 9

Pseudopelade of Brocq

Answer 9

• Scarring alopecia and fibrosis, end-stage follicular fibrosis, caused by primary inflammatory dermatosis such as LP, LE, pustular scarring forms of folliculitis, favus, scleroderma, and sarcoidosis

Question 10

Drug-induced LP, described distribution and name the offending drugs

Answer 10

• Symmetric eruption on trunk and exts, photodistribution
• 5-FU, carbamazepine, chlorpromazine, diazoxide, ethambutol, quinine/quinidine, tetracyclines, thiazides, and furosemide

Question 11

Name special forms of LP/lichenoid eruption (total 6)

Answer 11

• Drug-induced LP
• LP-lupus overlap
• Lichen planus pemphigoides
• Keratosis lichenoides chronica (Nekam Disease)
• LP and malignant transformation
• Lichenoid keratosis

Question 12

Lichenoid keratosis (LP-like keratosis)

Answer 12

• Sun-exposed skin of exts
• Histological features of LP with parakeratosis
• Co-occurs with solar lentigo, SK, and AK

Question 13

LP and malignant transformation, common sites

Answer 13

• Risk low to none at all
• Risk increases with longstanding disease, erosive, or atrophic type, tobacco use
• Common sites includes tongue, gingiva, buccal mucosa, with hx of either arsenic or X-ray exposure

Question 14

Lichen planus pemphigoides (differentiate from bullous LP)

Answer 14

• Either on top of LP lesion or de novo on uninvolved skin
• Bullous LP results from intense lichenoid inflammation and extensive liquefaction degeneration of basal keratinocytes
• Histologically LP with linear deposition of IgG and C3 at DE junction

Question 15

Name the offending drugs for lichenoid drug eruption (7 total)

Answer 15

• Beta-blockers, antimalarials, captopril, gold, penicillamine, HCTZ, NSAIDs

Question 16

Name the causative agents for lichenoid dermatitis (6 total)

Answer 16

• Color film developers, dental restorative materials, musk ambrette, nickel, aminoglycosides, gold

Question 17

Name medical conditions associated with LP

Answer 17

• Autoimmune chronic active hepatitis
• Primary biliary cirrhosis
• Postviral chronic active hepatitis
• HCV in some populations