Dr. McGurk,

I saw a 3 1/2 year old boy in clinic today with a history of autism and global develomental delay who has a significant habit of sucking on his thumb to the point where it is calloused with hypertrophic skin changes. What advice do you give for the developmentally appropriate child to stop thumb-sucking? Would any of this advice work for an autistic child? Should we even be concerned?

Thank you.

The quick answer is that I would leave it alone unless his thumb is eroded and infected and you're worried about, say, osteomyelitis.

First of all, a normal child of 3 1/2 could be considered totally normal to be thumb-sucking as a self-soothing behavior. This child, with a mental age of maybe two, would be even more likely to have a sucking habit. It gives you some appreciation for a pacifier, which can eventually be given up much more easily than a thumb.

Add the confusion of an autistic child whose ability to understand or organize social and language input, and you can see the advantage in a technique to help him calm and center himself. Unfortunately, normal self-soothing is not so easy to distinguish from the self-stimulation an autistic child might use to tune out the outside world. It's a spectrum, and he's young, so I'd put it in the normal range. The excess and the self injury are more characteristic of MR &/or autism, but almost every other problem he has is more serious. If it's a serious medical threat, I would just try barrier ointments (vaseline, desitin) and if it's infected bactroban, bandaging and try to switch him to another finger or maybe another soother-a transitional object, a blankie or a toy etc.

There was another thumb-sucking question several months ago which concerned the more general case of a normal child, if you're interested, which I answered in more detail. Yours, Harriet McGurk