Lichen planus

Lichen planus 

Updated: 12/18/2023

© Jun Wang, MD, PhD

General features
  • Likely immune disorder
  • More common in 30-60
  • May be confined to oral mucosa
  • Usually regressin 6 to 18 months
Pathogenesis
  • Cell-mediated (CD8+ T cells) immune response to antigens at basal cells or dermoepidermal junction, with unknown triggering factors
  • May be associated with immunity disorders, such as ulcerative colitis, dermatomyositis, etc, and certain infections, such as hepatitis C
  • Stressful events may play a role in the onset or exacerbation
Clinical features
Follicular: Lichenplanopilaris, hair follicles centered
Hypertrophic: Extremely pruritic, more common on extensor surfaces of lower extremities
Vesicular/bullous
Pathological features
  • Lichenoid inflammation: Band like chronic inflammatory infiltrate (T cells and macrophages) that destroys the dermoepidermal junction
  • Hyperkeratosis and acanthosis with prominent granular cell layer
  • Sawtoothing of rete pegs
  • Civatte bodies (apoptotic basal cells, PAS+)
  • Artifactual cleft formation at dermal epidermal junction
  • Occasional subepidermal bullae (Bullous lichen planus)
Immunofluorescence studies
Diagnosis
  • Commonly based on clinical findings
  • Biopsy (deep enough to include dermoepidermal junction) if uncertain
Management
  • Individualized treatment
  • Steroids, tropical or systemic, metronidazole, retinoids, etc.
  • UV-B radiation or psoralen with UV-A radiation for widespread cases
  • Usually self-limited  

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Contents

Pathology notes Jun Wang, MD, PhD 1. General information Frequently discussed syndromes Terms of dermatology Terms of hematology 2. Primary immunodeficiency disorders 3. Hemodynamic abnormalities Shock Thrombosis and embolism Bleeding disorders 4.  Benign blood cell disorders Anemia Benign white cell disorders 5. Hematopoietic neoplasms Lymphoid neoplasms Myeloid neoplasms Histiocytic neoplasms: Langerhans cell histiocytosis 6. Cardiovascular system Pulmonary hypertension Cardiovascular system tumors 7. Respiratory tract tumors 8. Gastrointestinal tract Congenital disorders Infectious gastroenteritis Oral cavity Esophagus Stomach Intestinal tumors Salivary glands Exocrine pancreas and gallbladder 9. Urinary system Kidney masses Lower urinary tract 10. Male reproductive system 11. Female genital tract 12. Breast 13. Endocrine organs Pituitary gland Adrenal gland Thyroid gland Parathyroid gland Endocrine pancreas M
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Anemia

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