Symptoms include: worry about losing parents or other attachment figures though illness or death; unreasonable fear of an event that causes separation (getting lost, say, or being kidnapped); reluctance or refusal to leave home for school; undue fear of sleeping or being alone; persistent nightmares about separation; and physical symptoms (headaches, stomachaches) in conjunction with separation or anticipation of separation. (childmind.org)
Places, people, animals, jobs, food, and «terms that incite undue fear» are out. (sciencemag.org)
What I tend to do is if hae undue fear about someting is to keep doing it until i either don't fear it any more or the fear becomes proprotionate to whatever is being expereinced. (nakedpastor.com)