Test Details: VDRL test is done to check or diagnose an infection with Treponema pallidum, which causes syphilis. Syphilis test is usually being prescribed in pregnant women as the presence may affect the foetus. If a person is being treated for any other STDs then a syphilis test can also be done to rule out infection. Symptoms of syphilis include painless sore, swollen lymph nodes, or skin rash.