LICHEN PLANUS

Lichen planus presents with very typical itchy papules, which are small
(1-3 mm) and are demarcated by the natural skin lines, making them
polygonal. They have a sharp, elevated border, a flat surface (hence the
name "planus") and they shine by reflecting light. They are often a shade
of red, later reddish blue to purple and show "Wickham’s striae", a fine
milky-white network on the papule’s flat surface. Neighbouring papules
may join together to form plaques which resemble lichen growing on
trees, explaining the name "lichen". They may occur anywhere on the skin
but are most common on joint flexures (especially wrists), genitals, sacral
region and inner thighs. A Koebner phenomenon is present. The oral
mucosa and lips may be affected and show a network of white lines.
Actinic lichen planus occurs on sun-exposed areas. In hypertrophic lichen
planus there are thick, hyperkeratotic papules and nodules or thickened
wart-like plaques on the shins. Lichen planus is self-limiting, it will disappear
spontaneously, sometimes in months but it may take many years.
Management of lichen planus
Treatment can be very difficult.
- For severe itch: calamine lotion and/or antihistamines.
- Coal tar 2-6% ointment nightly.
- Strong topical steroids combined
with salicylic acid 5% once to twice
daily.
- Refractive lesions: Apply strong
steroid at night and cover with
plastic 2 nights a week (see lichen
simplex). This improves penetration
of the steroid.
- Widespread, severe forms: a short
course of prednisolone may be tried:
start with 30 mg daily for a week
then reduce to zero in two weeks