Uncommon disorder of unknown cause, likely T-cell mediated autoimmunity against basal kertinocytes
Most common in patients aged 30 to 60 years
HCV association is controversial
Drug exposure can resemble idiopathic<unk> 
Skin (cutaneous<unk> 
Oral cavity (oral<unk> 
Genitalia (penile or vulvar<unk> 
Scalp<unk>  planopilaris)
Nails
Esophagus
Lichen planus
The differential diagnosis for lichen planus includes:
Lichen sclerosus
Chronic graft-versus-host disease
Tinea corporis
Psoriasis
Vitiligo
Atopic dermatitis