I understand it's a virus. Typically they appear as skin-colored bumps which often have a dimple in the center. In HIV-infected patients, MC can be quite severe, particularly on the face.
Children get MC quite commonly.
MC is also transmitted during sexual activity. They can even spread by shaving. In non-HIV infected individuals, MC usually persist for up to 6 months and then go away by themselves. In HIV'ers, MC usually are more persistent. My best advice, which I can give to you, is to have your MC removed.