"I have a problem that no one else I know has. I have a 3 year old daughter who never ever sucked her thumb or a dummy....until she was 3. She then changed child care centres and made friends with a thumb sucker at the new centre. I thought it was just a phase and didn't say too much to her about it. Unfortunately it has kept going for the last 6 months.
I wouldn't be too worried if she was just sucking her thumb for comfort or for naps, but she sucks her thumb ALL the time. She can be in the middle of a game and the thumb will sneak into her mouth. She is actually biting her thumb and has marks/scabs on both thumbs. I have been asking her to stop in a gentle way. Sometimes when I ask her to stop she says she's hungry....which leads me to believe she is biting her thumb! She does eat a lot (big meals and lots of snacks) so I don't think she actually is hungry.
Does anyone else have this problem? Any ideas of how to stop the behaviour or should I just wait it out?"
Yikes. I am normally not concerned about thumb-sucking, but this is the exception. The fact that she's sucking it all the time and leaving marks means it's going to damage her teeth. Plus, it's not good that she's continuing a behavior that must hurt her physically--it sounds like she's addicted to thumb-sucking.
I'm not sure there's any unhappy motivation for her sucking her thumb, though. It sounds to me like she was maybe stressed out about the child care switch, and that happened to intersect with her friendship with the child who sucks her thumb. Kids at this age are very susceptible to peer pressure (which is why some children potty train easily when they go to school or are around other kids who are potty trained), so she probably just took up thumb sucking because her friend did it and that made it cool.
But now it's spiraled out of control. 3-year-olds can be intense little creatures of habit, and my guess is that she's turned the thumb-sucking into a pressure valve for emotions while at the same time reinforcing it as a habit.
I do think you should try to stop it, but don't have a guaranteed method. I know I sucked my thumb (for comfort and bedtime) through the painted-on stuff that made my thumbs taste bad, and through all kinds of psychologically dicey methods my grandparents used (without my mom's knowledge) to try to get me to stop.
I'm wondering if addressing it with her as a safety issue (this is hurting your thumbs and it's also hurting your teeth) and then setting up a rewards system for going without sucking, or figuring out (together) some other thing she could do instead, would help.
Has anyone else successfully helped a chronic thumb-sucker to stop at this age? How did you work through it?