When I read this message I almost fell over this is the exact same thing that
When I read this message I almost fell over this is the exact same thing that
When I read this message I almost fell over this is the exact same thing that
I can't comment on the itching, but I think your chiropractor was very irresponsible to treat you 3-4 times a week with manipulation for that length of time.
If the neck (or any other joint) requires manipulation that often for that length of time, the dysfunction obviously stems from elsewhere in the spine - e.g. if the sacroiliac joints (pelvis) are unstable, it will create misalignment of the spine above it, including the neck.
Furthermore, if manipulation is administered too frequently, it will cause the ligaments to slacken - hence you were able to create the click yourself.
I would recommend finding a different practitioner.
Alterations in skull shape do not occur due to pressure alone after childhood when the skull bones fuse together and are no longer relatively soft.
Variations in skull size can occur slowly over time, due to certain diseases like acromegaly (excess growth hormone) or Paget' s disease (in older people), or in a more localized fashion by a disease of the bone, or an underlying inflammatory lesion under the bone which can cause some bony remodelling.
Variations could occur in the soft tissue overlying the skull over time in response to repeated trauma or pressure.
Objective measurements (like head cirumference, or by CT scan with 'bone windows' could be made and follwed over time to objectively record any changes in the skull