Livedo reticularis

What is livedo reticularis?

Livedo reticularis refers to a condition in which dilation of capillary blood vessels and stagnation of blood within these vessels causes mottled discolouration of the skin. It is described as being reticular (net-like) cyanotic (reddish blue discolouration) cutaneous discolouration surrounding pale central areas. It occurs mostly on the legs, arms and trunk and is more pronounced in cold weather.

When does it occur and who is at risk?

The appearance is due to altered flow in small blood vessels feeding the upper skin so that other vessels dilate to compensate. This can arise for a variety of reasons.

Cutis marmorata causes temporary livedo in about 50% of normal infants and many adults when exposed to the cold and is a physiological response to cold. It is more intense and persistent in conditions associated with debility and other factors that cause stasis within blood vessels. The mottling is diffuse, temporary, mild and usually symptomless.

Cutis marmorata

Cutis marmorata telangiectatica congenita is a rare condition in which the livedo is present at birth or soon after. There may be other congenital abnormalities including neurological and intellectual problems, and it can be familial. The livedo is usually severe but may improve with age.

Idiopathic livedo reticularis (i.e. cause unknown) occurs most commonly in young and middle-aged females, particularly during winter. Mottling occurs first only on exposure to cold but can become permanent. Tingling and numbness on cold exposure are common. Sometimes swelling, and rarely ulcers may develop in winter. In another less common variant, swelling of the feet and ankles and ulceration occurs in the spring and summer months.

Livedo reticularis

Sneddon's syndrome is a form of idiopathic livedo reticularis with systemic involvement i.e. internal blood vessels are affected, most commonly in the brain, eye and heart.

Secondary livedo reticularis is of known cause. It may be a sign of vasculitis (inflammation of the blood vessels) or of obstruction of the vessel by some circulating material. The following conditions may be responsible:

Vasculitis

• Livedoid vasculitis
• Polyarteritis nodosa
• Systemic lupus erythematosus
• Dermatomyositis
• Rheumatoid arthritis
• Lymphoma
• Pancreatitis
• Tuberculosis

Obstruction

• Cryoglobulinaemia (immune globulins that precipitate in the cold)
• Antiphospholipid syndrome (blood clots due to sticky platelets) or lupus anticoagulant syndrome
• Hypercalcaemia (calcium deposits)
• Polycythaemia rubra vera (excessive number of red cells) or thrombocythaemia (platelet clumps)
• Infections (syphilis and tuberculosis)
• Arteriosclerosis (cholesterol emboli) and homocystinuria
• Intra-arterial injection (especially in drug addicts)

Adverse reaction to medication

• Amantadine, used to treat Parkinson disease

What treatments are available?

There is no treatment for livedo reticularis. Rewarming the area in idiopathic cases or treatment of the underlying cause of secondary livedo may reverse the discolouration. However, over time the vessels become permanently dilated and livedo reticularis becomes permanent regardless of the surrounding temperature.