Licking everything

I am a Kindergarten teacher and I would like to know why this 5 year old girl licks everthing.  It could be her fingers or the shoes or table tops and even she licked the face of another child.  I was thinking that it could be a deficiency of some sort (vitamin or mineral?) or could it be Sensory Processing Desorder?  I would like to guide her parents to be able to get help.

[Kevin Kennedy, Ph.D.]

As with any behavior or symptoms, there can be multiple causes. The two you suggest are possibilities, as is the possibility of a motor tic. The behavior can also signify a condition along the pervasive developmental disorder spectrum and other developmental delays. The place to start would be an evaluation by a developmental pediatrician.