Sean Klepper M.D.
Stephen Lyle, M.D., ...
- "Five Ps": polygonal, planar (flat-topped), pruruitic, purplish papules and plaques, most commonly on flexor surfaces of the extremitites.
- Some cases are associated with hepatitis C.
- White lines called "Wickham's striae" are sometimes present.
- Compact hyperkeratosis
- Hypergranulosis (may be wedge-shaped)
- Irregular acanthosis with "saw tooth" rete ridges
- Colloid bodies (stain with IgM on immunofluorescence)
- Vacuolar change of the basal layer
- Lichenoid lymphocytic infiltrate
- Melanin incontinence is often present
- The presence of parakeratosis argues against the diagnosis of lichen planus.