Buttocks Lesion

I found this pimple like thing on my buttocks and it's painful when I sit. When I looked at it with my mirror I found it to look like a pimple and it's reddish around it. What should I do?

[unnoticed16]

I'm sure I had no sex. So I don't think it is from STD's.

[Dr_Aparna]

Hi,
This could be due to a boil or folliculitis, bith of which are varying degrees of inflammation of the hair follicle.

Folliculitis is a superficial infection of the hair follicles characterized by erythematous(red),  follicular-based papules and pustules. Furuncles(boils) are deeper infections of the hair follicle characterized by inflammatory nodules with pustular drainage, this accounts for their painful nature.

Topical treatment with clindamycin 1% or erythromycin 2%, applied two to three times a day to affected areas, coupled with an antibacterial wash or soap, is adequate for most patients with folliculitis.

Additionally,you can  treat the area with warm compresses three to four times a day for 15-20 minutes, to bring the boil to a head and hasten the discharge.
Oral antibiotics are not required unless associated with infection of tne surrounding tissue.

ref:http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/dermatology/commonskin/commonskin.htm

[unnoticed16]

The bump started to harden up today. I saw on warm water yesterday for 10 minutes, and I applied polysporin to the bump. It contains Bacitracin 500 units and Polymyxin B 10,000 units.