You are having alopecia areata. this is an autoimmune condition due to the attack of lymphocytes​ against hair roots. It results in the formation of bald patches. It can affect any hairy area of the body also like scalp, eyebrows and  beard. It has to be treated properly for long duration until the immunity comes down. Once the immunity is controlled, hair grows back over the patches. Please contact me using online consult option for proper prescription. I cannot prescribe medicine here in common chat.