Brief Answer:
You need to take antibiotics

Detailed Answer:
I have studied your case and reviewed the picture submitted. I think you are most probably having a bacterial infection and need to take antibiotics for it. But before you take any medication I would recommend you to visit a doctor and take his advise. I give following suggestions to my patients with similar complains.
1. Take NSAID like Brufen one or two tablet daily.
2. Take broad spectrum antibiotic like Doxycyclin one tablet daily.
3. Some time minor surgery can be needed to drain the abscess.

Keep the area clean and dry; avoid scratching or or using any ointment locally. Check your blood sugar as these type of infections are common in Diabetes Mellitus.

I hope these answer will be useful for you. Let me know if there is any other followup questions.

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Brief Answer:
first you need to show it to doctor

Detailed Answer:
Hello,
Pus drainage and antibiotics both can be done simultaneously. By looking at your image I think some pus is already there so I would recommend you to visit doctor. If doctor feels it is necessary than he will drain the pus.
Antibiotics are not effective is pus is there. So I would suggest you to visit doctor and than start antibiotics. It may be six days to twelve days course.
thanks.

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