Nodules Identified on the Backs of Hands in Adults with Dupuytren's Disease
Physicians often rely on visible changes in the skin and joints to identify and diagnose problems like Dupuytren's disease. Dupuytren's disease (also known as Dupuytren's contracture) is a fairly common disorder of the fingers. It most often affects the ring or little finger, sometimes both, and often in both hands.

Normally, we are able to control when we bend our fingers and how much. How much we flex our fingers determines how small an object we can hold and how tightly we can hold it. People lose this control as the disorder develops and the palmar fascia contracts, or tightens. This contracture is like extra scar tissue just under the skin. As the disorder progresses, the bending of the finger becomes more and more severe, which limits the motion of the finger.

Although the exact cause is unknown, it occurs most often in middle-aged, white men and is genetic in nature, meaning it runs in families. This condition is seven times more common in men than women. It is more common in men of Scandinavian, Irish, or Eastern European ancestry. The disorder may occur suddenly but more commonly progresses slowly over a period of years. The disease usually doesn't cause symptoms until after the age of 40.

Your doctor can tell if you have a Dupuytren's contracture by looking at and feeling the palm of your hand and your fingers. Usually, special tests are unnecessary. Abnormal fascia will feel thick. Cords and small nodules in the fascia may be felt as small knots or thick bands under the skin. These nodules usually form first in the palm of the hand.

Bumps or nodules on the backs of the hands (dorsum or dorsal side) are also linked with this condition. Various terms have been used to describe these changes. Two of the most common descriptors include knuckle pads and dorsal nodules. The medical term for knuckle pads is dorsal cutaneous pads (DCPs). The medical term for the nodules is dorsal Dupuytren's nodules (DDN).

The pads are described as thickening, sclerosis, and loss of skin elasticity. The nodules are solid tumor-like masses over the back of the finger joints (knuckles). Some physicians think these two features (pads and nodules) are the same thing. Other experts believe the two are separate symptoms. They may not both be a sign of Dupuytren's.

This study was done in order to see if there is a difference between these two entities and to find out if both are part of the Dupuytren's condition. Two groups of adults were compared. The first group had a known diagnosis of Dupuytren's. The second (control) group were considered normal, healthy individuals without Dupuytren's.

Two hand surgeons examined the hands of all 100 participants looking for any signs of pads or nodules as defined above. They recorded how many skin lesions each person had and the location as well as what the skin changes looked like. Background on each participant was also collected such as age, family medical history, ancestry and ethnicity, and occupation or type of current employment. The surgeons also examined each person's feet to look for similar symptoms.

After examining all the lesions and data collected, the surgeons found that knuckle pads and nodules are, indeed, two separate skin changes. Visibly, the pads are more like little cushions. The nodules look and feel like hard knots. And the nodules were more likely to be part of the Dupuytren's disease.

More people in the control (normal) group (without Dupuytren's) had knuckle pads -- probably as a reaction to work or trauma or maybe as part of some type of skin condition. The control group did not have any nodules. And a closer examination of the nodules from people with Dupuytren's showed that the tissue inside the nodules was exactly the same as the more common nodules found on the palmar side of the hand.

Several observations were made from this study. First, although people with Dupuytren's can have both dorsal cutaneous (knuckle) pads and dorsal nodules, people in the control group (normal, healthy adults) only had the knuckle pads (no nodules). Joints and fingers affected differ between pads and nodules. Knuckle pads seem to affect multiple fingers. Nodules appear at single sites and usually affect the index or small finger.

The authors concluded that 1) knuckle pads and dorsal nodules are two separate things, 2) the knuckle pads are not a sign of Dupuytren's, and 3) these two entities (pads and nodules) when found on the hands should be considered as different from one another. They advise further studies to continue examining differences between knuckle pads and nodules and a clearer understanding of why these develop.
Ghazi M. Rayan, MD, et al. Dorsal Pads Versus Nodules in Normal Population and Dupuytren's Disease Patients. In The Journal of Hand Surgery. October 2010. Vol. 35A. No. 10. Pp. 1571-1579.