PERIPHERAL VASCt LAR DISEASES 



[227 



due to vascular changes in the reticular-perpendicular 

 arterioles in the skin of these sites. 



Manifestations other than the typical color changes 

 may be present. During the pallid or cyanotic crises, 

 digital paresthesias may be present. During the 

 erythematous phase there may be increased warmth 

 and a painful throbbing sensation in the affected 

 digits. After long-standing or severe disease, ulcera- 

 tion, necrosis, edema, or subungual and paronychial 

 infection may develop (fig. 3). Ulcers usually occur 

 on the digital tips and these may be quite painful. 

 When they heal, they typically leave small pitted 

 "stellate" scars. Another change that occasionally 

 develops in long-standing or severe disease is sclero- 

 dactylia. The digits show a tight, tough, inelastic, 

 fibrotic, and contracted skin with areas of hyper- 

 pigmentation and hypopigmentation. This change 

 must be differentiated from a) acrosclerosis, in which 

 similar changes involve not onlv the digits but also 

 the face and neck; and b) scleroderma, in which 

 fibrotic changes are generalized, even involving 

 multiple visceral organ systems. 



Practically nothing is known of the earliest patho- 

 logic changes in Raynaud's disease. This is due in 

 large part to the lack of biopsy specimens obtained 

 during the early stages of the disease. Physicians 

 and investigators have been reluctant to obtain 

 biopsies in these patients. Simple digital biopsy 

 methods and other means are now available whereby 

 early changes may be observed, both by light and 

 electron microscopy not only in Raynaud's syndrome 

 but also in other peripheral vascular disorders (32, 

 73, 75). Based on light microscopy, it has been 

 assumed that pathologic changes are absent in early 

 Raynaud's disease. More sensitive methods, such as 

 electron microscopy, may alter this impression. In 



FIG. 3. Primary Raynaud's disease with trophic changes 

 and early sclerodactylia. 



the later stages of the disease, intimal thickening of 

 the digital arteries is almost always present. In still 

 more advanced stages the internal elastic membranes 

 split and there is endarteritis obliterans with thrombi 

 in various stages of recanalization. The latter changes 

 are particularly frequent in association with 

 ulceration. 



Briefly, and in general, the mechanisms for Ray- 

 naud's phenomenon are as follows: Pallor is due to 

 digital arterial constrictive crises to the point of, or 

 almost to the point of, complete occlusion with 

 resultant absence or near absence of digital arterial 

 blood flow. Capillary pressure drops to about 5 to 10 

 mm Hg (60). Cyanosis occurs when digital arterial 

 constrictive crises are slightly less severe, allowing 

 some blood to flow. In this situation the slow rate 

 of flow fosters an increased dissociation of ox\ gen 

 from hemoglobin with resulting local cyanosis. 

 During the recovery phase from the vasoconstriction, 

 erythema frequently ensues due to reactive hyperemia. 

 These physiologic changes are fairly well accepted 

 as the vascular reactions responsible for the typical 

 digital color changes. Controversy still exists, how- 

 ever, regarding the location and nature of the under- 

 lying factors responsible for initiating vascular reac- 

 tions. Raynaud felt that the primary factor was a 

 derangement of the nervous system (84). Adson & 

 Brown (2) also considered the basic fault in early 

 Raynaud's disease to exist entirely in the vasomotor 

 nerves, since complete relief of Raynaud's reaction 

 occurred in many patients following sympathetic 

 ganglionectomy. 



Lewis (48, 49), however, maintained that the 

 basic fault is in the digital arteries themselves and 

 that the defect consists of an abnormal sensitivity 

 of the arteries to direct stimuli, particularly to cold. 

 In Lewis' own words (49), "The central fact is tran- 

 sient loss of circulation to the digits occurring on 

 exposure to cold. I have shown that this spasmodic 

 loss of circulation is due to closure of the digital 

 arteries, and that, irrespective of its nature, the fault 

 lies in these vessels; the closure does not involve 

 arteries of much larger size, neither does it include 

 arterioles or veins. But since the attack is induced by 

 exposure to cold, to which all vessels normally 

 respond, a general reduction of their size happens. 

 In most of the vessels the degree of closure can be 

 regarded as no more than normal. In the small 

 arteries only is the response to cold manifestly abnor- 

 mal; these are in a state rendering them particularly 

 liable to shut on direct exposure to cold. In sensitive 

 cases, the blood-flow to a single finger can be arrested 



