5. Immune-mediated dermatosis,
It involves skin, hair follicles, nails and/or mucosae (Oral,
Vulvovaginal)
There are several clinical types of lichen planus that share
similar features on histopathology.
6. Skin, Six P’s :
Planar (Flat-topped).
Purple (Post- hyperpigmentation).
Polygonal.
Pruritic (Rubbing rather Scratching).
Papules.
Plaques.
Mucosa : Wickham striae
Nail : Onychorrhexis, Onychoschezia, Dorsal Pterygium,
Trachyonychia, and Anonychia.
Characteristics
7. Skin, Six P’s :
Planar (Flat-topped).
Purple (Post-Inflammatory hyperpigmentation).
Polygonal.
Pruritic (Rubbing rather Scratching).
Papules.
Plaques.
Mucosa : Wickham striae, Macroscopic appearance shows
hypergranulosis
Nail : Onychorrhexis, Onychoschezia, Dorsal Pterygium,
Trachyonychia, and Anonychia.
Characteristics
8. ➢ Exact cause is Unknown.
➢ Genetic predisposition : MHC-1 (HLA-B7,8), MHC-2 (HLA DR1,10).
➢ Associations : Hepatitis C (Oral LP)
Aetiology
➢ Drugs : NSAIDs, ACEIs, Chloroquine, Mercury, Gold injections (in the past),
nickel sensitivity seen in oral LP.
and Ulcerative colitis, Alopecia areata, Vitiligo and dermatomyositis.
29. Genital LP / Penile LP
• Site: glans penis.
• Clinically: classical papules in a ring around the glans. White streaks and
erosive lichen planus may occur but are less common.
• DDx/ Eczema, Psoriasis, Fixed drug eruption..