Neck hair is missing, called retrograde alopecia (photo)
https://healthell.blogspot.com/2021/10/neck-hair-is-missing-called-retrograde.html
This happens to some men as they get older. They lose their neck hair as shown here. This is a very extreme example of retrograde alopecia...
from BaldingBlog - Hair Loss Info https://ift.tt/2ZI0KTa