Suggest Treatment For Recurring Boil In Butt Crack

my wife has had a boil for about a couple of weeks she has been taking antibiotics and i have been applying itchthammol on her. The boil is located near the butt crack its on the left butt cheek but really close to the crack.It is the second time it comes out in the same spot.She had it cut open and drained about a couple of months ago.It was big then ,and now as well it is about 2-3 inches big hard and puffed.There is still no head. We dont have insurance and were wondering should we go to the doctor and if so which specialty should it be we have no idea