A 29 year old woman has developed an itchy scaly rash

A 29 year old woman has developed an itchy scaly rash particularly over her wrist with
fine white streaks overlying the lesion. Her nails have ridges and her buccal mucosa is
lined with a lacy white pattern. What is the SINGLE most likely diagnosis?
A. Psoriasis
B. Scabies
C. Lichen planus
D. Dermatitis herpetiformis
E. Candida infection
Lichen planus
Lichen planus is a skin disorder of unknown aetiology, most probably being immune
mediated.
Features

  • Purple, pruritic, papular, polygonal rash on flexor surfaces
  • Lacy white pattern on buccal mucosa
    Mnemonic: 4P
    Purple
    Pruritic
    Papular
    Polygonal rash