Livedo reticularis is a common cutaneous finding consisting of a mottled reticulated vascular pattern that appears like a lace-like purplish discoloration of the lower extremities. The discoloration is caused by swelling of the medium veins (not small) in the skin, which makes them more visible. It can be caused by any condition that makes venules swell.

The condition may be normal or may be related to more severe underlying pathology

Pathology

Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....

. It has a broad differential diagnosis, broadly divided into possible blood diseases, autoimmune (rheumatologic) diseases, heart (cardiovascular) diseases, cancers, and endocrine disorders. It can usually (in 80% of cases) be diagnosed by biopsy.

It may be aggravated by exposure to cold and occurs most often in the lower extremities.

The condition's name derives from the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 livere meaning bluish and reticularis which refers to the reticular visual impression.

Etiology

A number of conditions may cause the appearance of livedo reticularis:

• Cutis marmorata telangiectatica congenita
  Cutis marmorata telangiectatica congenita
  Cutis marmorata telangiectatica congenita or CMTC is a rare congenital vascular disorder that usually manifests in affecting the blood vessels of the skin. The condition was first recognised and described in 1922 by Cato van Lohuizen, a Dutch pediatrician whose name was later adopted in the other...
  
   a rare congenital condition
• Sneddon syndrome
  Sneddon syndrome
  Sneddon's syndrome is a form of arteriopathy characterized by several symptoms, including:* cerebrovascular disease* Livedo Reticularis or Livedo Racemosa* hypertension...
  
   - association of Livedoid vasculitis and systemic vascular disorders, such as strokes, due to underlying genetic cause.
• Idiopathic livedo reticularis - the most common form of livedo reticularis and is a completely benign condition of unknown cause affecting mostly young women during the winter. It is a lacy purple appearance of skin in extremities due to sluggish venous blood flow. May be mild, but ulceration may occur later in the summer.
• Secondary livedo reticularis:
  • Vasculitis
    Vasculitis
    Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...
    
     autoimmune conditions
    Autoimmunity
    Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
    
    :
    • Livedoid vasculitis
      Livedoid vasculitis
      Livedo reticularis is a common cutaneous finding consisting of a mottled reticulated vascular pattern that appears like a lace-like purplish discoloration of the lower extremities. The discoloration is caused by swelling of the medium veins in the skin, which makes them more visible...
      
       - with painful ulceration occurring in the lower legs
    • Polyarteritis nodosa
      Polyarteritis nodosa
      Polyarteritis nodosa is a vasculitis of medium & small-sized arteries, which become swollen and damaged from attack by rogue immune cells. Polyarteritis nodosa is also called Kussmaul disease or Kussmaul-Maier disease...
      
      
    • Systemic lupus erythematosus
      Systemic lupus erythematosus
      Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...
      
      
    • Dermatomyositis
      Dermatomyositis
      Dermatomyositis is a connective-tissue disease related to polymyositis and Bramaticosis that is characterized by inflammation of the muscles and the skin.- Causes :...
      
      
    • Rheumatoid arthritis
      Rheumatoid arthritis
      Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
      
      
    • Lymphoma
      Lymphoma
      Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...
      
      
    • Pancreatitis
      Pancreatitis
      Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...
      
      
    • Tuberculosis
      Tuberculosis
      Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
      
      
    • Amantadine
      Amantadine
      Amantadine is the organic compound known formally as 1-adamantylamine or 1-aminoadamantane. The molecule consists of adamantane backbone that has an amino group substituted at one of the four methyne positions. This pharmaceutical is sold under the name Symmetrel for use both as an antiviral and an...
      
       (drug)
  • Obstruction of capillaries:
    • Cryoglobulinaemia - proteins in the blood that clump together in cold conditions.
    • Antiphospholipid syndrome
      Antiphospholipid syndrome
      Antiphospholipid syndrome or antiphospholipid antibody syndrome , often also Hughes syndrome, is an autoimmune, hypercoagulable state caused by antibodies against cell-membrane phospholipids that provokes blood clots in both arteries and veins as well as pregnancy-related complications such as...
      
       due to small blood clots
    • Hypercalcaemia
      Hypercalcaemia
      Hypercalcaemia is an elevated calcium level in the blood. . It can be an asymptomatic laboratory finding, but because an elevated calcium level is often indicative of other diseases, a workup should be undertaken if it persists...
      
       (raised blood calcium levels which may be deposited in the capillaries)
    • Haematological disorders of Polycythaemia rubra vera
      Polycythemia
      Polycythemia is a disease state in which the proportion of blood volume that is occupied by red blood cells increases...
      
       or Thrombocytosis
      Thrombocytosis
      Thrombocytosis is the presence of high platelet counts in the blood, and can be either primary or reactive...
      
       (excessive red cells or platelets)
    • Infections (syphilis
      Syphilis
      Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
      
      ,tuberculosis, lyme disease)
    • Assc with Acute Renal Failure due to cholesterol emboli status post cardiac cath.
    • Arteriosclerosis
      Arteriosclerosis
      Arteriosclerosis refers to a stiffening of arteries.Arteriosclerosis is a general term describing any hardening of medium or large arteries It should not be confused with "arteriolosclerosis" or "atherosclerosis".Also known by the name "myoconditis" which is...
      
       (cholesterol emboli) and homocystinuria
      Homocystinuria
      Homocystinuria, also known as cystathionine beta synthase deficiency or CBS deficiency, is an inherited disorder of the metabolism of the amino acid methionine, often involving cystathionine beta synthase...
      
       (due to Chromosome 21
      Chromosome 21 (human)
      Chromosome 21 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. The trisomy of the 21st chromosome causes Down Syndrome...
      
       autosomal recessive Cystathionine beta synthase deficiency)
    • Intra-arterial injection (especially in drug addicts)
  • Ehlers-Danlos Syndrome
    Ehlers-Danlos syndrome
    Ehlers–Danlos syndrome is a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen . The collagen in connective tissue helps tissues to resist deformation...
    
    -- connective tissue disorder, often with many secondary conditions. Livedo Reticularis may be present in all types.

Treatment

Other than identifying and treating any underlying conditions in secondary livedo, idiopathic livedo reticularis itself may improve with warming the legs, but once established the skin discolouration may become permanent.