The ITIN# is not the same as the SSN# and it should not be substituted for the SSN#. A state requires the SSN# to know that you can work legally in the US, the ITIN# is issued when one does not have permission to work in the US, but needs a number for taxes, such as they are here under the H-4 visa.
Be aware that the state has the right to cancel out a license if they find that the ITIN# was substituted for it. Remember that one has to submit the SSN# to the BON for any state when they obtain it and how are you going to explain that you had submitted the ITIN# to get around the laws here.
Please be very careful in doing this. If a state was accepting of the ITIN#, it would be listed on their application, and then they also would not require the SSN# for licensure in the first place.
