spot on left buttock

I have a spot on my left buttock that is now red, sore and itchy.  The day before it became a 2" eruption on my skin, I noticed a hard knot under the skin, kind of similar to a large pimple getting ready to appear.  This is the third time this has occured in the past 3 years, in the same area.  I've gone to the doctor thinking I may have gotten bitten by a spider, because after a few days it starts to dry out and get itchier and spread a little more.  The doctor didn't think it was a spider bite but told me to get some antibacterial soap which seems to help a bit, but I'd like to know what the heck is causing it because it is also painful at times to sit.  Any help would be appreciated.  BTW, I'm a 51 year old female in pretty good health.

[Bhupinder Kaur, MD]

Hello,
It can be due to a boil on the buttocks. A boil generally starts as a reddened, tender area. Over time, the area becomes firm and hard. Eventually, the center of the abscess softens and becomes filled with pus. Finally, the pus "forms a head," which can be surgically opened or spontaneously drain out through the surface of the skin.

Boil on buttocks is usually due to plugged sweat glands that become infected or by an ingrown hair.

Apply warm compresses on the boil and keep the area clean. Drainage of the boil is done only when it becomes soft and forms a head. Take some over the counter pain reliever and consult a doctor for examination and antibiotics prescription. If there are recurrent boils, then pls get your blood sugar levels estimated.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.