Skin tag causes. Skin tags are hereditary growths that most often occur around the neck, underarms, under breasts and inner thighs. They are benign but can be unattractive and uncomfortable at times. Friction and heredity can be linked to their appearance, although sometimes they seem to be random.
Skin tags. Skin tags can occur almost anywhere on the body covered by skin. However, the two most common areas for skin tags are the neck and armpits. Other common areas for the development of skin tags include the eyelids, upper chest (particularly under the female breasts), buttock folds, and groin folds. Tags are typically thought to occur in characteristic friction locations where skin rubs against skin.