Livedo reticularis is an erythema of the skin caused by a blood flow disorder, also known as “mottling”. Often purple and red, in reticulated form, these marks form a network of meshes on the skin. What are the causes and symptoms? How to treat them?

This little used medical name comes from Latin, livedus, which means “bluish”.

Livedo is the purplish and red mottles that appear on the skin, forming a network of meshes, giving it a marble appearance. Completely painless, it is a benign anomaly of the skin due to the blood circulation and often the cold.

We sometimes differentiate the so-called reticulated livedo (reticularis) from the branched livedo (racemosa).

The first is a regular fine and closed mesh, of benign origin; the second with open regular mesh, asymmetric, of secondary origin. But in general, we will call all livedo as the reticulate (reticularis), making it difficult to distinguish between the two.

The location of these mottles can be on the back, arms or legs. Livedo can be either physiological or pathological.

In the case of livedo physiological

No disease is involved here. It appears by exposure to cold. As soon as the affected limb warms up, livedo disappears. It is usually located on the lower limbs (legs). Livedo reticularis is most often physiological.

In the case of livedo pathological

This therefore comes from the effects of contracted diseases, for example:

• cancers ;
• abnormality of blood containers (hyperplasia, arthritis, etc.);
• endocrine or nutritional diseases, such as hypothyroidism;
• infectious diseases such as pneumococcal sepsis;
• intake and combination of certain drugs (erythromycin and levastatin);
• nervous system disorders;
• abnormal blood content, such as hyperviscosity in the blood;
• embolies;
• vasomotor disorders (contraction or relaxation of blood vessels).

Livedo pathological is always due to an abnormality of the blood content, or to a thickening of the vascular wall. It reaches areas such as the trunk, has open meshes, and presents extra-cutaneous signs, for example neurological.

This is a permanent, “fixed” livedo.

However, many livedos present both physiological and livedo pathological criteria. It is not always possible to tell them apart. By observation of the field, the associated clinical signs, the presence of additional pathological examinations and the evolution, it will be possible to issue a diagnosis to judge whether it is one or the other.

As we have seen, livedo is characterized by purplish meshes on the skin. The cold can often accentuate the symptoms observed.

Physiological livedo

In the first case, the physiological livedo:

• then appears from childhood, at the level of the limbs;
• has small closed meshes;
• subsides when lying down;
• is idiopathic (we do not know the cause), but it disappears on warming of the limb;
• is often isolated and without other associated signs;
• is present without infiltration or necrosis.

The pathological livedo

In the second case, the pathological livedo:

• appears on the trunk and legs;
• features open mesh, sizes small to large;
• is present permanently;
• is often the cause of infiltration or necrosis of the extremities;
• has associated skin signs;
• is associated with a disease that causes it.

Livedo reticularis (reticularis)

• Made up of fine and regular knits which always close on themselves.
• Is most often physiological.
• Is attenuated when lying down and disappears on warming.

Branched livedo (racemosa)

• It consists of large, irregular, open, asymmetrical and often suspended meshes.
• It still requires an assessment and monitoring.

In the case of a physiological livedo, it will simply be treated by avoiding the cold. Since as soon as the skin warms up, livedo disappears.

However, concerning livedo pathological, there is no specific treatment. Depending on the pathology implicated in the appearance of livedo, the results of the assessments carried out, a therapeutic management may be decided. We can in any case carry out an investigation at the level of blood tests (CBC, coagulation assessment for example), in order to help make a diagnosis.

Some livedos require rapid recognition since they can be of concern for the functionality of the observed limbs. An adapted and quickly applicable treatment will prevent significant skin lesions, and sometimes visceral or cardiac lesions, which can become disabling.