The signs and symptoms of lichen planus vary depending on the areas affected. Typical signs and symptoms are: 
Purplish, flat bumps, most often on the inner forearm, wrist or ankle, and sometimes the genitals
Itching
Blisters that break to form scabs or crusts
Lacy white patches in the mouth or on the lips or tongue
Painful sores in the mouth or vagina
Hair loss
Change in scalp color
Nail damage or loss
