The first thing you need to consider is baldness, and the second thing you need to consider is due to syphilitic alopecia. 1. Patch baldness: Patch baldness can show a patch of bald hair, the cause is not yet completely clear, may be related to heredity, autoimmune diseases, stress, endocrine disorders, mental tension, etc., can occur at any age, there can be a single or multiple round, oval, border clear area of hair loss. 2. Syphilitic alopecia: a patch of bald hair may also belong to syphilitic alopecia, belonging to the performance of the second stage of syphilis, most of them are sparse, the border is not clear, similar to the worm erosion. Hair a piece of baldness, it is recommended that patients go to the hospital as soon as possible to improve the examination, a clear diagnosis, and then follow the doctor’s instructions to take standardized treatment, not to ignore the symptoms, to take it lightly.