Skin nontumor
Lichenoid and interface reaction patterns
Pityriasis lichenoides chronica
Topic Completed: 1 August 2011
Minor changes: 10 November 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Pityriasis lichenoides chronica [title]
Table of Contents
Definition / general | Case reports | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Additional referencesCite this page: Hamodat M. Pityriasis lichenoides chronica. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorPLC.html. Accessed March 6th, 2021.
Definition / general
- Presents with red-brown papules with wafer-like scale
- Overlaps with pityriasis lichenoides et varioliformis acuta
- Shows predeliction for males in late childhood and early adulthood
- Involve the arms, legs, trunk and buttocks; flexors are more commonly affected than the extensors
- Associated with itching and burning sensation
- Some seasonal variation, worsening in winter and some improvement in sunlight
Case reports
- 19 year old woman with pityriasis lichenoides chronica (Dermatol Online J 2004;10:8)
Clinical images
Contributed by Mark R. Wick, M.D.
Arms
Breast skin
Microscopic (histologic) description
- Similar to PLEVA, but less destructive
- Parakeratosis present in well-demarcated zones; vacuolar interface change and lymphocyte exocytosis less than PLEVA
- Wedge shaped pattern of dermal lymphocytic infiltrate
- The chronic lesion shows parakeratosis with lymphocytes, similar to Munro microabscesses of psoriasis
- Purpura is often present
Microscopic (histologic) images
Contributed by Mark R. Wick, M.D.
Breast skin
Positive stains
- IgM and C3 in the walls of the superficial dermal blood vessels
Additional references
