What is it?
Livedo reticularis is a term referring to the appearance of a “net-like”, red-blue pattern on the skin.
There are a number of different types of livedo reticularis:
- Cutis marmorata
This term refers to the condition in infants and young children. It is usually a normal temporary response to the cold. However, in rare cases, this pattern is persistent and caused by an underlying congenital disorder.
- Physiologic livedo reticularis
This term refers to a temporary skin response to cold exposure.
- Primary or idiopathic livedo reticularis
This term refers to the persistent skin pattern in an otherwise healthy individual.
- Secondary livedo reticularis
This term refers to the persistent skin pattern associated with an underlying medical disorder.
What does it look like?
This appears as a mottled discolouration of red and blue resulting in a net-like appearance of the skin. It is usually symmetrical. It often affects the lower limbs, but the trunk and upper limbs may also be affected.
What causes it?
Generally, livedo reticularis arises from altered blood flow in the skin microcirculation (the small blood vessels that supply the skin). A variety of factors reduces the flow of fresh arterial blood to the skin. This leads to the collection of venous blood and gives rise to the typical purplish colour.
Cold weather can induce the arteriolar walls to spasm. However, in physiologic livedo reticularis, the pattern tends to disappear when the affected area is warmed.
Other causes include reduced blood flow due to hyperviscosity (thickened consistency of the blood), vessel wall pathology (e.g. from blood vessel inflammation) or obstruction (e.g. from a blood clot inside the vessel).
What other problems can occur with this condition?
- Primary livedo reticularis
People with primary livedo reticularis usually do not have symptoms other than the appearance of the condition. Numbness and tingling have been reported in rare cases.
- Secondary livedo reticularis
- Secondary livedo reticularis is associated with the following underlying disorders:
- Connective tissue disorders (particularly systemic lupus erythematosus and dermatomyositis)
- Thrombophilia (an underlying increased tendency for blood clots to form). A person with thrombophilia could have a history or risk of stroke, deep vein thrombosis, pulmonary embolism or pregnancy loss
- Vasculitis (inflammation of the blood vessel wall)
- Endocrine (hormone) disorders
- Medication-related disorders.
How is it diagnosed?
The diagnosis is usually made by a dermatologist, based on the appearance of the condition.
Blood tests are performed to diagnose possible underlying causes. A skin biopsy may also provide a clue to the underlying related condition.
Primary livedo reticularis is a “diagnosis of exclusion” which means that the term is only used if no other cause can be detected.
How is it treated?
Usually no treatment is required in physiologic livedo reticularis and it is enough for affected individuals to avoid the cold. Where the cosmetic concern is great, the area can be camouflaged.
With secondary livedo reticularis, it is important to identify and treat the underlying condition.
What is the likely outcome of it?
The chance of making a good recovery from primary livedo reticularis is excellent.
In secondary livedo reticularis, the likely outcome relates to the underlying disorder.
This information has been written by Dr Charlotte Thomas and Associate Professor Pablo Fernández Peñas
Updated 14 March 2017