A lice-killing lotion containing 1% permethrin or a mousse containing pyrethrins and piperonyl butoxide can be used to treat pubic (crab) lice. These products are available over-the-counter without a prescription at a local drug store or pharmacy. These medications are safe and effective when used exactly according to the instructions in the package or on the label. Lindane shampoo is a prescription medication that can kill lice and lice eggs.
Trichomoniasis is another type of vaginal infection. It is caused by a single-celled parasite that is usually spread through sex. In addition to causing bleeding after sex, it can also cause vaginal discharge and itching.
Causes of bleeding after sex. Bleeding after sex can be a sign of a health condition: 1  an infection, such as pelvic inflammatory disease (PID), or a sexually transmitted infection (STI), such as chlamydia.  vaginal dryness (atrophic vaginitis) caused by reduced vaginal secretions after the menopause.