New mole? Have a small scaly brown bump appear on hand. Itched for a few days and is now sore to touch and red around it. History of atypical moles.

Have it biopsied. Anyone with a history of atypical moles who develops new moles with scaliness and itching should have it biopsied. The redness around the mole may represent inflammation from scratching it or more remote possibility of an infection. See your pcp or your plastic surgeon.
New moles devlop ove. Moles do not develop so quickly and the atypical moles(nevi) are typically brown or back and not raised. If you are concerned about this one, go see your doctor who has told you about your previous (atypical) moles.
Biopsy. With a history of atypical moles, any new or changing lesions (especially a printed one) should be removed and tested (biopsied).