Diabetic cheiroarthropathy (DCA) or pseudosclerodermatous hand of the diabetic is characterized by nonpainful limited extension of the proximal metacarpophalangeal and/or interphalangeal joints with spontaneous flexum of the fingers. The mechanism of lesion formation is poorly known but apparently associates neurogenic, vascular and cutaneous phenomena. Fifteen patients with DCA (9 men, 6 women; range 20-74 years) were studied by capillaroscopy, photoplethysmography and skin biopsy. Eleven had type 1 diabetes and 4 type 2 over periods ranging from 1 to 42 years (mean 19.9 years). Diabetic retinopathy was noted 10/15 times, nephropathy 5/15 times and neuropathy of the lower limbs 13/15 times. All patients had at least one of these abnormalities. In capillaroscopy, "Shoal of fish" features of diabetic microangiopathy were found only 4 times, but minor dystrophy was noted in 12 cases. In digital photoplethysmography, a drop in digital systolic pressure or an increase in pulse time was noted in 5 cases. The Hillestad test was less than or equal to 2 in 8 patients. Histological study showed constant dermal collagenous fibrosis in diseased skin, which was also found in normal skin in 6/13 patients. PAS staining showed a thickening of vascular basal membrane 14/15 times in diseased skin and 11/13 times in normal skin. The relation between DCA and microangiopathy is discussed in terms of collagen metabolism abnormalities observed during diabetes.