The bump may be gray, pink, red, or the same color as your skin. It's often covered by a yellow or brown crust. Sometimes it's easier to feel than to see. It tends to feel like sandpaper.
A lump on the back of your neck also can be a part of a food allergy response, or an allergic reaction to laundry detergents, skin and hair care products, or medication. Symptoms With a Lump on the ...