Lichen planus

dermatology

1. Lichen Planus

2. Definition “ Dermatosis of unknown origin characterised by typical violaceous papular eruption on characteristic sites and white mucosal lesions.” ( dermatosis means non-inflammatory lesion which involves integumentary system)

3. Pathogenesis Lichen planus is a T cell-mediated autoimmune disease, in which inflammatory cells attack an unknown protein within skin and mucosal keratinocytes . HLA-3 , HLA-5

4. Etiology Associated with other immune conditions e.g. ulcerative colitis , alopecia areata , vitiligo etc . Genetic predisposition 1-2% Associated with hepatitis C virus infection. Koebner`s phenomena Drugs e.g. gold , quinine , arsenic , isoniazid , streptomycin , photocolor developer , dental amalgam Complication of bone marrow transplant

5. Involves: Skin Mucous membrane Legs Scalp Genitalia

6. Patient presents with : Pin-point papules/ polygonal plaques Grouped /discrete Well-marked itching Initially , they develop on flexures and later generalised eruption occurs .

7. 5Ps

8. Common sites : Wrists and forearm Lumbar region Lower legs and ankles

9. Chronic lesions Palms and soles : yellowish hyperkeratotic papules Nail changes Thinning Longitudnal lines Pterygium (scar)

10. Wickham`s straie

11. Mucosal lesion Network of white streaks characteristic

12. Colour changes Early lesion Late lesion

13. Legs( develops into chronic hypertrophic)

14. Palms, soles

15. Lichen- planopilaris

16. Nails

17. Prognosis Acute attack clears in 6-9 months . Ordinary type 6-18 months . Hypertrophic types takes several years .

18. Diagnosis Clinically Biposy may be taken to confirm and look for complication i.e SCC Patch test : in case of oral lesions to check for mercury allergy .

19. Treatment Acute : topical steroids , antihistamine . Hypertrophic : intralesional steroid , oral antihistamine . Severe local/systemic : oral prednisolone

20. Other options for widespread disease : Narrow-band or broadband UV-B therapy  Psoralen with UV-A (PUVA) therapy Azathioprine cyclosporin

21. Thank you !