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.
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. 2  vaginal dryness (atrophic vaginitis) caused by reduced vaginal secretions after the menopause.