Question

*an itchy palm and *an itching palm
Fig. [of a hand] in need of a tip. (As if placing money in the palm would stop the itching. *Typically: get ~; have ~; give someone ~.)
  All the waiters at that restaurant have itchy palms.
  The cabdriver was troubled by an itching palm. Since he refused to carry my bags, I gave him nothing.
   Whenever he sees expensive luggage, the hotel doorman gets an itching palm.