I have developed a bald patch on my beard on the upper lip. it does not itch and the skin is not discoloured. what can be the causes and therapy?

Alopecia Areata: Alopecia areata is a common autoimmune skin disease resulting in the loss of hair on the scalp and elsewhere on the body. It usually starts with one or more small, round, smooth patches. Treatment is with topical cortisone or cortisone shots injected into the area of hair loss. This condition may be associated with thyroid disease and or anemia.