The main reason is that the skin of the nipple is infected with bacteria, mostly Streptococcus haemolyticus, and the most important feature of this bacteria is that the infection is prone to the phenomenon of blood blisters and rashes at the site of infection. Therefore, after the occurrence of bloody nipple exudate should be actively treated, including local treatment, you can disinfect the blood bubble local iodophor, apply erythromycin ointment or Bactrim ointment, through anti-inflammatory symptomatic treatment, can alleviate the blood bubble rupture and the spread of inflammation. For the more serious ones, you can also consider applying antibiotic drugs, such as amoxicillin and penicillin V potassium tablets commonly used clinically for oral or static dosing, the blistered nipples can gradually improve.