I am a 20 year old male who is worried about some hair loss at the neckline / nape of the neck region. I currently do not have any signs of balding on the crown or the hairline, but for some reason, every time I pull on the sides of the neck hairline, one or two tapered hairs fall out. My question is whether or not androgenic alopecia can affect that region or if that region is determined by other genetic factors? 

In some individuals, the neck hair is genetically programmed to fall out early. Rarely have I seen this in a 20 year old, but not uncommon in a man over 35. A few hairs may not mean that you are losing neck hair but just normally cycling hairs