The recurrence of flat warts may be caused by factors such as incomplete cure, low immune function, direct or indirect contact, and so on. 1. not completely cured: after suffering from flat warts disease, in the process of treatment, after the disappearance of the symptoms on their own to stop using medication, there may still be infections, in the body of the lower immunity will be recurrence. 2. low immune function: the body overworked, suffering from chronic diseases or chronic infections, may lead to the body immunity is lowered, it is easy to make flat warts recurrence. 3. direct or indirect contact: direct contact with the infection or with the flat warts patients share some supplies, such as towels, bath towels, etc., can lead to flat warts recurrence.