"Knarley" Knuckles in a 12-year-old Boy

A 12-year-old boy, being seen for a respiratory illness, takes the opportunity to ask his doctor what's wrong with his fingers; actually, it's the knuckles he's concerned about, as is his mother.What do Michelangelo's statues of David and Moses have to do with the case of Knuckles McGee?Find out as you click through this next in Dr Jon Schneider's ongoing series of very interesting cases. How would you dignose these "knarley" knuckles.Scroll down for resources.            Resources (alphabetical order by author)Barnes CJ. Knuckle pads. http://emedicine.medscape.com/article/1074379-overview#showall. Updated: Jul 14, 2016. Accessed March 17, 2017.Hyman CH, Cohen PR. Report of a family with idiopathic knuckle pads and review of idiopathic and disease-associated knuckle pads. Dermatol OnLine J. 2013;19:8. 5Morginson WJ. Discrete keratodermas over the knuckle and finger articulations. JAMA Arch Derm. 1955;71:349-353. doi:10.1001/archderm.1955.01540270061007Nenoff P, Woitek G. Knuckle pads. NEJM. 2011;364:25.Paller A, Herbert A. Knuckle pads in children.  Am J Dis Child. 1986;140:915-917.Tamborrini G, Gengenbacher M, Bianchi S.  Knuckle  pads – a rare finding. J Ultrasonograph. 2012; 12:493–498. https://www.researchgate.net/publication/287327810_Knuckle_pads_-_a_rare_finding