I get these knot or cyst whatever it is called under my arm and when it bust smelly pus begins to ooze out and last night when I was changing my bandage I notice the head was not white like it has always been it had a dark appearance to it and as I began to squeeze it something that looks like a black rock feel out of it really freaked and grossed me out what could this be?
Hi. Thanks for your query and an elucidated history. This is a boil-now got infected with typical bacteria which form dark-colored pus and is smelly too. It is better to get an antibiotic and anti-inflammatory medicines as this may not settle and may get spread to the nearing area. Keep the area clean with applying liquid provide iodine thrice daily. Consult a Doctor to get a prescription.