Deformity and disability minimization is critical after irreversible nerve impairment has occurred.
The following is a diagram of the secondary progressive disability changes that follow primary nerve impairment of sweat, sensory and muscle function.
Loss of sweat glands in the skin:
- The loss of sweat glands in the skin leads to dry callused skin which frequently crack at joints and at fingertips.
- Cracks or lesions in the skin are openings for infection since the skin serves as a natural barrier to infection.
Loss of sensibility:
- Numbness and tingling or a loss of feeling can occur due to a loss of sensitive receptors in the skin which provide touch and pain feedback to the nervous system.
- Wounds and infections from sharp objects, small objects and handles can occur from the abnormally high pressures concentrated in the thumb and fingertips that have lost their natural sense of how hard an object is being gripped.
- nfection which is chronic or frequent and repetitive high pressure at fingertips, leads to reabsorption of bone and soft tissue resulting in shortened fingers and, if severe, can result in the loss of fingers.
Loss of selective muscle function:
- When the small muscles of the hand are weakened or lost with preservation of larger, stronger muscles that originate higher in the forearm as often happens in Hansen's disease, a muscle imbalance is created and fingers can be damaged when the hand is used.
- Muscles which at first appear weak can become totally paralyzed, increasing the degree of impairment.
- Deformity can result from abnormally high pressures at the fingertips caused by the strong overpull of muscles extrinsic to the hand when the hand pinches or grips without the smaller muscles which serve to balance and stabilize the force of these other muscles.
- Deformity can be progressive once damage has occurred to ligaments, joints, bone and other tissue. These are more likely to be repetitively injured from similar factors.