Strange lump on top of finger?

hi i'm 15 and my brother is 14 and we both have a strange lump, that started smalled and now looks swallen. It s strange that we both have it. i had this for bout a week. Could it be a alergic reaction of some sort. It isnt really much of a lump its more feels like a blister, but is a bit harder and is red. So it isnt really a lump more swallen red and some tiems feels a bit burning underneath the skin. nothing else a bove the skin except it being a bit red, swallen and slightly hard with little pain.
I probly shouldnt have much to worry about, if its some sort of cyst i hope i dotn have to get it reomoved. I hope it can just go away on its own i just h8 docters. sounds stupid lol i just do.

i hope if anyone else would give me a idea what it mite be and what i should do about it.