I am a 33 year old white female who is almost over a sinus infection, cold or allergy. About three nights ago I discovered about a one inch roundish swollen slightly raised area on my scalp (located about 2 inches above my hair line at my neck and about 3 inches back from my ear). This is an area that is totally covered by my hair. I went to an urgent care clinic and the Doctor told me it was not a lymphatic gland because it is not in an area where there is a lymph gland. She said it was most likely a cyst and not related to my nasal drainage and not to worry about it. She put me on amoxicillin for my sinus drainage. Could a cyst of that size (about one inch) come very quickly, almost acute? I did not notice it earlier in the day and I know it wasn't there the day before. It feels a bit swollen when I touch it. Otherwise physically I feel great and the sinus drainage is completely gone. What could this be? Would something malignant come that acutely? If it's still there in a few weeks would there be any harm in me getting my hair routinely dyed? I am very worried about this. Should I be?