There is ambiguity about using the term "knuckle pads" in Dupuytren's disease (DD). Clear definitions of dorsal knuckle pads and nodules are lacking and the prevalence of these 2 entities has not been determined. We sought to define these terms and investigate the distribution and frequency of dorsal knuckle pads and dorsal nodules in the normal volunteers and in DD patients.
We assessed 50 consecutive study patients with DD and a convenience sample group of 50 control patients without DD for dorsal cutaneous pads (DCP) (ie, thickening, sclerosis, and loss of skin elasticity) and dorsal Dupuytren's nodules (DDN) (ie, solid tumor-like masses over the digital joints). Demographic information was collected for both groups, including the extent of the disease in DD patients. We examined both groups for the presence of dorsal lesions and their characteristics, and the DD patients for other local and ectopic Dupuytren's lesions and for the level of diathesis.
None of the control patients had DDN, whereas 9 DD patients had DDN (p = .002). Nine control patients had DCP, whereas 11 DD patients had DCP (p = .803) Among the 9 control patients with DCP, pads were predominantly over the proximal interphalangeal joints and tended to occur in men with physically demanding occupations, and in the dominant hand. The index and long fingers were most frequently affected. Six patients had only DCP, 4 had only DDN, and 5 had both DDN and DCP. In the control and study groups, the DCP characteristics and patients' demographic data were comparable. Patients with DDN were white men with physically undemanding occupations and had lesions over the proximal interphalangeal joints, most frequently in the index finger, with an average size of 6 mm. Neither DCP nor DDN were encountered in the thumb.
Future studies should clearly distinguish between DCP and DDN. Although DDN are pathognomonic of DD, DCP demonstrates similar prevalence in normal and DD populations.