Lichen planus

    Article Contributors: 
    Sean Klepper M.D.
    Stephen Lyle, M.D., ...

    Clinical Features:

    • "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.

     

    Histologic Features:

     

    • 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.
    External Links

     

     

    Cases associated with this book:

  • Lichen planus
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection