Lichen Planus

Question 1

What is lichen planus?

Answer 1

Chronic inflammatory, puritic skin disorder

Question 2

Mechanism behind lichen planus

Answer 2

T-cell mediated autoimmune disorder (most likely)

Associated with hepatitis infection

Question 3

Histology of lichen planus

Answer 3

Irregular sawtooth acanthosis
(Acanthosis = an increase in the number of prickle cells in the innermost layer of the epidermis)
Hypergranulosis (increased granular layer)
Orthohyperkeratosis (thickening of the keratin layer with non-nucleated keratinocytes)

Question 4

Presentation of lichen planus

Answer 4

Very itchy, purple-pink (violaceous), polygonal, shiny, flat topped papules and plaques
Common on the flexors of the wrists, forearm, shins and ankles
Wickham’s striae = whitish lines visible in the papules
Nail ridges
White lesions on inside of the mouth
Can affect the inside of the vagina

Question 5

Treatment of lichen planus

Answer 5

Generally resolves spontaneously within a year
Topical steroids
Oral steroids (if extensive)