Hi, My Friend Has A Very Swollen, Red And Tender

Hi, my friend has a very swollen, red and tender to movement, pus filled bump on his hand. It is in between his thumb and pointer finger. It seem to be getting more swollen and seems to be accumulating more white pus as the day goes on. It has a small pin sized, dark colored dot in the middle of it. Can someone please tell us what this might be? He says its very uncomfortable. Thank you.