Hand Function in Scleroderma

Skin involvement is present in all SSc
patients and has a centripetal course,
affecting hands and face early and electively,
with the potential involvement
of all the other skin areas. In SSc, skin
involvement evolves through oedematous,
sclerotic and atrophic phases.
Hand disability develops since oedematous
phase, in which oedema reduces
fingers movement and hands functionality.
Oedema is prominently related to
the microangiopathy of the lymphatic
vessels, contemporary to the microangiopathy
of the blood microvessels,
causing leakage of fluid and macromolecules
in the interstitial tissues (6).
In the following sclerotic phase, the
skin becomes fibrotic, increases its
consistency and becomes inelastic,
impossible to be lifted in folds, shiny,
tight and adherent to the subcutaneous
tissue. In the later atrophic stage, the
skin is thinned, due to the reduction in
thickness of the dermis.
In the hands, the progressive skin sclerosis leads, firstly, to flexion deformity of
the fingers and, then, to the typical disabling
claw hands, characterised by ankylosis
in flexion of the proximal and distal
interphalangeal (IP) joints, loss of flexion
of the metacarpophalangeal (MCP)
joints, loss of mobility of the thumb,
blocked in adduction and flexion. The
reduction of flexion-extension of the
wrist is concomitant. In the atrophic
stage, hand movements are further reduced,
especially with regard to pronation-supination
of the radio-ulnar joint