Sorry I have no idea. However wounds that are open and remain bleeding for a long period of time (days) is not a thing one should put off seeing a doctor for. Considering how close it is to your privates, I am more worried for the possibility of complications via other infections. a very small sore could be a lesion which have many causes from viral disease to cancers: http://tray.dermatology.uiowa.edu/DDX-Morph.html And open wound (slightly different than a lesion) can be caused by a bug bite to a pimple to a cut - it remaining open and bleeding can be from excess moisture (its location means you keep it under clothing all the time) or it can be due to an infection in the wound that is not allowing it to close and heal. Allergic reactions to things like metal, plastics placed against the skin can lead to ulcers (lesions) which are open wounds that remain open if kept in contact. For instance the elastic in the leg of your panties may be composed of a type of rubber that you are sensitive too (allergic to) which has lead to rash and irritation which has progressed to a wound. Again, due to the location of the wound i would strongly urge seeing a health professional. If you do not have insurance or are covered for medical, nearly every county has a public health department which has doctors on sliding scale or even for free. Since this is bleeding all the time this may even be worth an ER trip if not ER then critical care, same day clinic. Different places have different programs for instance our county hospital has both an Emergency Room for people in need of serious health care, and a Critical care department which is similar to ER, except the people are not in too bad of shape.