Synonym: Garrod's pads
Clinical features:
(1) fibrous thickening of the skin that are well-circumscribed, smooth, skin colored papules or plaques
(2) often located on the dorsal aspect of the proximal interphalangeal (PIP) joints of the finger but can occur on the knuckles (metacarpophalangeal joint)
(3) usually asymptomatic but occasionally may be painful
The tend to occur in conditions with the joint undergoing repeated trauma:
(1) repetitive occupational trauma
(2) contact sports (athlete's nodules or surfer's nodules)
(3) video game controller
(4) bulimia ("vomiting pads")
(5) anxiety or obsessive-compulsive disorder ("chewing pads")
Other conditions associated with knuckle pads include:
(1) Dupuytren disease
(2) Bart Pumphrey Syndrome (BPS), with palmoplantar keratoderma
(3) acrokeratoelastoidosis Costa
(4) pseudoxanthoma elasticum
(5) esophageal cancer
Occasionally no underlying condition is identified (idiopathic).