If you are worried it is best to get your GP to check it out, although normally if it is sore it is nothing serious.

I had the same thing recently, and although the skin never erupted it turns out it was a boil deep under the skin. This is caused from anti-perspirant clogging up the pores of the skin. Now I just use deodorant instead.

It could also be an ingrowing hair, very painful in such a sensitive area.

Keep an eye on it for the next few days, if it continues to be painful or gets any worse make an appointment to see your doctor.

Hi. I woke up one morning and noticed the same thing. Thing is I have other symptoms also. Do you notice any changes or differences in your health? Did this lump ever go away? Mine was pretty big. It hurt and was tender to the touch. But weird thing is it went away after a few days. But I have noticed other lymph nodes starting to get swollen in other areas. Some hurt and some don't. Your best bet is to keep an eye on it and track your symptoms. I always do that and it's the main reason after five years I was able to get a couple diagnosis. Never let anyone tell you any different. You know your body and you know when something isn't right. I wish you well.