MBBS VII Semester Dermatology Learn all you need about Lichen Planus with students of BPKIHS, Dharan, Nepal.

1. Lichen Planus
Dr. Prajwal Pandey
Department of Dermatology

2. Introduction
• Lichen
• Lichenoid
– Clinical
– Histological
• “bandlike” infiltrate of mononuclear inflammatory cells
(predominantly lymphocytes) immediately subjacent to the
dermal–epidermal junction
• Lichen Planus

3. • Relatively common (1% of all dermatology
visits)
• Most often affects middle-aged adults, female
slightly more than male
• Both skin and mucosa are involved
– Examination of all sites essential if suspected

4. Primary lesions of LP
• ‘P’s in LP
– Plentiful
– Pruritic
– Polished
– Purple
– Polygonal
– Plane
– Papules/plaques
• Wickham’s stria
– Only diagnostic clue in
mucosal involvement
– Can be enhanced by drop
of mineral oil
• Isomorphism

6. Primary Symptom
• Onset: acute or insidious
• Pruritus often intense
• Special quality of pruritus
– Induces rubbing rather than scratching for relief
– May account for polished appearance
• Koebnerization
– New lesions at the site of excoriation

7. Sites of
predilection

8. Characteristic oral/mucosal finding
• Involved in 50% of LP, sole manifestation in 10%
• Wickham’s stria, in absence of papular component
– White, retiulated, netlike pattern
– Buccal mucosa, tongue, other mucosal surface
• Asymptomatic to erosive form: erosive gingivitis
• Some cases associated with dental amalgams
(mercury)
– Mercury-associated lichenoid stomatitis
• 25% involvement in genital mucosa

9. Pathogenesis
• Cause unknown
• Hypotheses
– Hypersensitivity reaction
– Viral infection (hepatitis C)
– Autoimmune mechanisms
• Lichenoid eruptions
– Drugs
– Graft vs host disease (bone marrow transplant)
• Dental amalgum
• Idiopathic (most cases)

11. Less common presentations
• Nail changes
– 10 – 15 %
– Longitudinal ridging, irregular pitting, nail plate splitting, nail
loss
– Pup tent sign: tenting of nail plate
– Pterygium formation
– 20 nail dystrophy
• Desquamative vaginitis
• Annular LP in glans
– characteristic

12. Variants
• Clinical and histological variants
– Annular
– Hypertrophic
– Ulcerative
– Vesicobullous/ LP pemphigoides
– Actinic
– Lichen planopilaris (follicular)
• Scarring alopecia in scalp involvement
• Frontal fibrosing alopecia

14. Associated systemic diseases
• Viral hepatitis (HCV)
– Association in East/Southeast Asia, South America, Middle East
and Europe
– Ask Hx of: IV drug use, high risk sexual behavior, blood
transfusion
• Chronic active hepatitis
• Primary biliary cirrhosis
• Diabetes mellitus
• Internal malignancy
• Autoimmune or connective tissue disease

15. Prognosis
• Duration related to the site of involvement
• Isolated mucosal lesions
– More chronic (lasting decades)
– Increased risk of SCC
• Isolated cutaneous lesions
– Typical spontaneous resolution, 1-2 years
• Both mucosal and cutaneous involvement
– Intermediate prognosis
• Persistent and recalcitrant
– Ulcerative, Palmoplantar and actinic variants

16. Histopathology
• Hyperkeratotic stratum corneum, essentially no
parakeratosis
• Granular layer focally accentuated: wedge shaped
hypergranulosis
• Malphighian layer irregularly thickened: sawtooth
acanthosis, civatte bodies in superficial dermis
• Interface reaction: lost or flattened basal layer
• Bandlike lymphocytic infiltrate with vacuolated and
obscured DEJ: lichenoid infiltration

18. Treatment
• Pruritus in mild cases
– Topical corticosteroids
– Oral antihistamines
• Severe disease
– Optimal treatment difficult to determine
– Systemic corticosteroids most commonly
– Topical calcineurin inhibitors (tacrolimus, pimecrolimus)
– Psoralen UVA, narrow-band UVB
– Oral retinoids (isotretinoin and acitretin)
– Others: Dapsone, griseofulvin, methotrexate, cyclosporine,
sulfasalazine, thalidomide

19. Treatment
Guidelines

20. Differentials
• Lichenoid drug eruption
– Atypical distribution
– Lack of mucosal involvement
– Histopathology
• significant parakeratosis
• eosinophils within the inflammation
• Lichenoid contact dermatitis
– Chemicals involved in photodeveloping

21. Common drugs implicated in Lichenoid
Drug Eruption

22. LP and other rare associations
• LP-SLE overlap syndrome
– SLE diagnosed in patients with LP
– Papulosquamous lesions of SLE in acral area may resemble
LP
• Lichen planus pemphigoides
– Overlapping features of LP and bullous pemphigoid
– Bullous lesions arising on LP-like papules and normal skin
• Lichenoid eruptions in GVHD
– More generalized than classic LP
– Clinically and histologically indistinguishable