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HANDBOOK OF PHYSIOLOGY 



CIRCULATION II 



FIG. 5. Livedo reticularis (lower portions of both 

 legs of patient lying supine). 



Lewis (49) noted, however, the arterioles in affected 

 areas are in an unusually high state of tone. He was of 

 the opinion that this is due to a fault in the vessels 

 themselves, since anesthetizing the appropriate 

 nerves does not result in prompt relief of the arteriolar 

 spasm, as it would if the mechanism were neural in 

 origin. In contrast, observations by Day & Klingman 

 (17) were interpreted as showing predominant sym- 

 pathetic nervous influences as the basic mechanism. 

 They noted that during sleep the cyanosis and cold 

 skin are relieved and replaced by warm, red skin. 



No definitive studies are available in acrocyanosis 

 concerning the significance of tissue catecholamines 

 and other vasoactive substances. Nevertheless, com- 

 ments made above on Raynaud's disease in this 

 regard might be equally applicable here. 



Since the course of acrocyanosis is relatively benign 

 and complications are few, sympathectomy has rarely 

 been indicated in its treatment. Because of this, con- 

 trolled studies on the effects of sympathectomy are 

 unavailable. In severe cases, however, sympathectomy 

 may be of value, especially when there is an associated 

 hyperhidrosis. The usual protection from cold or 

 sudden and marked decline in temperature is indi- 

 cated. The patient should keep warm and dry with 

 serious attention being given to his general state of 

 health. 



livedo reticularis. Livedo reticularis is character- 

 ized by a prominent mottled, reticular, or blotchy 

 reddish-blue discoloration of the skin of the extremi- 

 ties (fig. 5). Between the reticular discolorations, the 

 skin presents a more normal but pale appearance. 



Kaposi was probably the first to use the term 

 "livedo reticularis" (3). The etiology of this disease 



is unknown. That it may represent a congenital 

 anomaly of blood vessels has been suggested by 

 some (85, 103). Some are of the opinion that there 

 is some inherent vascular instability in the back- 

 ground of most patients (3). In one series, 30 per 

 cent of the patients had associated hypertension and 

 50 per cent demonstrated marked nervous instability 

 (3, 5). Livedo reticularis is more frequent in females 

 and usually appears before the age of 40. 



The disorder usually involves the skin of the legs 

 and feet in greatest severity, but it frequently also 

 involves the arms and hands. Occasionally, the thighs 

 and the lower part of the trunk may be affected. 

 There is a distinct tendency for the disease to occur 

 bilaterally and symmetrically. 



The characteristic color changes are usually in- 

 tensified on exposure to cold and tend to be alleviated 

 on exposure to a warm environment. Patients may 

 complain of numbness, tingling, coldness, or aching 

 over the involved legs and feet. Ulcerations in livedo 

 reticularis are not frequent but they do occur. Ulcers 

 usually begin as an intensification of change in 

 areas of marked cyanosis, usually over the medial 

 lower one-third of the leg. These lesions may be very 

 painful and slow to heal. Ulcers in some patients 

 seem to be precipitated by cold weather, whereas in 

 others warm weather seems to be important in their 

 formation (23). 



The pathophysiology and clinical findings in 

 livedo reticularis have been the subject of several 

 reports (20, 48, 85, 103); the most recent one of sig- 

 nificance is by Feldaker el al. (23). The latter authors, 

 following the suggestion of Williams & Goodman 

 (103), preferred to classify livedo reticularis into 

 three groups: /) cutis marmorata, 2) idiopathic 



