Scleroderma (progressive systemic sclerosis) is a systemic autoimmune disorder 
characterised by skin sclerosis, calcinosis and changes in microvasculature. The 
etiology of the disease is unknown but both genetic and environmental factors 
have been implicated. Telangiectasia (macroscopically visible dilated skin 
vessels) occurring primarily on the hands and face, are a prominent feature in 
scleroderma and are present in the majority of patients. Similarly, 
telangiectasia are found in patients with hereditary hemorrhagic telangiectasia 
(HHT), a mutational disorder of the germline genes endoglin and ALK-1, members 
of the TGFbeta receptor family, expressed on endothelial cells. Our study 
investigated the number, distribution and microscopic characteristics of 
telangiectasia in both limited (n = 29) and diffuse scleroderma (n = 9) and 
compared findings with 3 patients with HHT. In limited scleroderma, the mean 
number of telangiectasia (hand and face) was 36 (0-150) compared with 23 (0-135) 
in diffuse scieroderma. A significant correlation was observed between the 
number of telangiectasia on the face and on the hands (p = 0.014). The total 
number of telangiectasia correlated significantly with the disease duration (p = 
0.009). The spatial distribution of the telangiectasia appeared to be random on 
both hands and foreface in contrast with the distribution of subcutaneous 
calcification of the hands which occurred predominantly on the distal and flexor 
surfaces of the first, second and fifth digits. Nailfold microscopic 
capillaroscopy was performed on 12 patients. No significant correlation was 
observed between capillary diameter or density and with total number of 
telangiectasia observed macroscopically. The distribution and microscopic 
appearance of telangiectasia in scleroderma appeared very similar to those 
observed in HHT. In view of these similarities we therefore conclude that 
telangiectactic development in scleroderma may be associated with disorders of 
the TGFb receptor family proteins found on the microvasculature.